Multicenter experience with valve-in-valve transcatheter aortic valve replacement compared with primary, native valve transcatheter aortic valve replacement.

BACKGROUND: Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) offers an alternative to reoperative surgical aortic valve replacement. The short- and intermediate-term outcomes after ViV TAVR in the real world are not entirely clear. PATIENTS AND METHODS: A multicenter, retrospective analysis of a consecutive series of 121 ViV TAVR patients and 2200 patients undergoing primary native valve TAVR from 2012 to 2017 at six medical centers. The main outcome measures were in-hospital mortality, 30-day mortality, stroke, myocardial infarction, acute kidney injury, and pacemaker implantation. RESULTS: ViV patients were more likely male, younger, prior coronary artery bypass graft, "hostile chest," and urgent. 30% of the patients had Society of Thoracic Surgeons risk score <4%, 36.3% were 4%-8% and 33.8% were >8%. In both groups many patients had concomitant coronary artery disease. Median time to prosthetic failure was 9.6 years (interquartile range: 5.5-13.5 years). 82% of failed surgical valves were size 21, 23, or 25 mm. Access was 91% femoral. After ViV, 87% had none or trivial aortic regurgitation. Mean gradients were <20 mmHg in 54.6%, 20-29 mmHg in 30.6%, 30-39 mmHg in 8.3% and ≥40 mmHg in 5.87%. Median length of stay was 4 days. In-hospital mortality was 0%. 30-day mortality was 0% in ViV and 3.7% in native TAVR. There was no difference in in-hospital mortality, postprocedure myocardial infarction, stroke, or acute kidney injury. CONCLUSION: Compared to native TAVR, ViV TAVR has similar peri-procedural morbidity with relatively high postprocedure mean gradients. A multidisciplinary approach will help ensure patients receive the ideal therapy in the setting of structural bioprosthetic valve degeneration.

Comparative effectiveness of revascularization strategies for early coronary artery disease: A multicenter analysis.

OBJECTIVES: The goal of this analysis was to examine the comparative effectiveness of coronary artery bypass grafting versus percutaneous coronary intervention among patients aged less than 60 years. METHODS: We performed a multicenter, retrospective analysis of all cardiac revascularization procedures from 2005 to 2015 among 7 medical centers. Inclusion criteria were age less than 60 years and 70% stenosis or greater in 1 or more major coronary artery distribution. Exclusion criteria were left main 50% or greater, ST-elevation myocardial infarction, emergency status, and prior revascularization procedure. After applying inclusion and exclusion criteria, the final study cohort included 1945 patients who underwent cardiac surgery and 2938 patients who underwent percutaneous coronary intervention. The primary end point was all-cause mortality stratified by revascularization strategy. Secondary end points included stroke, repeat revascularization, and 30-day mortality. We used inverse probability weighting to balance differences among the groups. RESULTS: After adjustment, there was no significant difference in 30-day mortality (surgery: 0.8%; percutaneous coronary intervention: 0.7%, P = .86) for patients with multivessel disease. Patients undergoing surgery had a higher risk of stroke (1.3% [n = 25] vs 0.07% [n = 2], P < .001). Overall, surgery was associated with superior 10-year survival compared with percutaneous coronary intervention (hazard ratio, 0.71; 95% confidence interval, 0.57-0.88; P = .002). Repeat procedures occurred in 13.4% (n = 270) of the surgery group and 36.4% (n = 1068) of the percutaneous coronary intervention group, with both groups mostly undergoing percutaneous coronary intervention as their second operation. Accounting for death as a competing risk, at 10 years, surgery resulted in a lower cumulative incidence of repeat revascularization compared with percutaneous coronary intervention (subdistribution hazard ratio, 0.34; 95% confidence interval, 0.28-0.40; P < .001). CONCLUSIONS: Among patients aged less than 60 years with 2-vessel disease that includes the left anterior descending or 3-vessel coronary artery disease, surgery was associated with greater long-term survival and decreased risk of repeat revascularization.

Galectin-3 as a Predictor of Long-term Survival After Isolated Coronary Artery Bypass Grafting Surgery.

BACKGROUND: Galectin-3 (Gal-3) is a well-established biomarker of adverse clinical outcomes, but its prognostic value for long-term survival after cardiac surgery is not well understood. Elevated levels of Gal-3 have been found to be remarkably associated with higher risk of death in both acute decompensated and chronic heart failure populations. Its prognostic value for long-term survival after cardiac surgery is not known. METHODS: A sample of patients contributing to the Northern New England Cardiovascular Disease Study Group Cardiac Surgery Registry from 2004 to 2007 were enrolled in a prospective biomarker cohort (N = 1690). Preoperative Gal-3 levels were measured and categorized by quartile. We used Kaplan-Meier survival analysis and Cox regression models, adjusting for variables in The Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategy probability calculator to evaluate the association between elevated Gal-3 levels and survival to 6 years. RESULTS: Preoperative Gal-3 levels ranged from 1.72 to 28.89 ng/mL (mean, 8.96 ng/mL; median, 8.06 ng/mL; interquartile range, 5.42-11.08 ng/mL). Crude survival decreased by increasing quartile. After adjustment, serum levels of Gal-3 in the highest quartile of the cohort were associated with significantly decreased survival compared with the lowest quartile (hazard ratio [HR] 2.22; 95% confidence interval [CI], 1.40-3.54; P = .001). No decrease in survival was found for the middle quartiles (HR 1.36; 95% CI, 0.87-2.12; P = .177). CONCLUSIONS: A substantial association was found between elevated preoperative Gal-3 levels and risk of mortality after isolated coronary artery bypass grafting surgery. An assessment of the relationship between preoperative serum biomarkers and long-term survival can be used for risk stratification or estimating postsurgical prognosis.

Tissue versus mechanical aortic valve replacement in younger patients: A multicenter analysis.

OBJECTIVE: The goal of this study was to examine the long-term survival of patients between the ages of 50 and 65 years who underwent tissue versus mechanical aortic valve replacement (AVR) in a multicenter cohort. METHODS: A multicenter, retrospective analysis of all AVR patients (n = 9388) from 1991 to 2015 among 7 medical centers reporting to a prospectively maintained clinical registry was conducted. Inclusion criteria were: patients aged 50 to 65 years who underwent isolated AVR. Baseline comorbidities were balanced using inverse probability weighting for a study cohort of 1449 AVRs: 840 tissue and 609 mechanical. The primary end point of the analysis was all-cause mortality. Secondary end points included in-hospital morbidity, 30-day mortality, length of stay, and risk of reoperation. RESULTS: During the study period, there was a significant shift from mechanical to tissue valves (P < .001). There was no significant difference in major in-hospital morbidity, mortality, or length of hospitalization. Also, there was no significant difference in adjusted 15-year survival between mechanical versus tissue valves (hazard ratio, 0.87; 95% confidence interval [CI], 0.67-1.13; P = .29), although tissue valves were associated with a higher risk of reoperation with a cumulative incidence of 19.1% (95% CI, 14.4%-24.3%) versus 3.0% (95% CI, 1.7%-4.9%) for mechanical valves. The reoperative 30-day mortality rate was 2.4% (n = 2) for the series. CONCLUSIONS: Among patients 50 to 65 years old who underwent AVR, there was no difference in adjusted long-term survival according to prosthesis type, but tissue valves were associated with a higher risk of reoperation.

The Association between Cytokines and 365-Day Readmission or Mortality in Adult Cardiac Surgery.

Cardiac surgery results in a multifactorial systemic inflammatory response with inflammatory cytokines, such as interleukin-10 and 6 (IL-10 and IL-6), shown to have potential in the prediction of adverse outcomes including readmission or mortality. This study sought to measure the association between IL-6 and IL-10 levels and 1-year hospital readmission or mortality following cardiac surgery. Plasma biomarkers IL-6 and IL-10 were measured in 1,047 patients discharged alive after isolated coronary artery bypass graft surgery from eight medical centers participating in the Northern New England Cardiovascular Disease Study Group between 2004 and 2007. Readmission status and mortality were ascertained using Medicare, state all-payer claims, and the National Death Index. We evaluated the association between preoperative and postoperative cytokines and 1-year readmission or mortality using Kaplan-Meier estimates and Cox's proportional hazards modeling, adjusting for covariates used in the Society of Thoracic Surgeons 30-day readmission model. The median follow-up time was 1 year. After adjustment, patients in the highest tertile of postoperative IL-6 values had a significantly increased risk of readmission or death within 1 year (HR: 1.38; 95% CI: 1.03-1.85), and an increased risk of death within 1 year of discharge (HR: 4.88; 95% CI: 1.26-18.85) compared with patients in the lowest tertile. However, postoperative IL-10 levels, although increasing through tertiles, were not found to be significantly associated independently with 1-year readmission or mortality (HR: 1.25; 95% CI: .93-1.69). Pro-inflammatory cytokine IL-6 and anti-inflammatory cytokine IL-10 may be postoperative markers of cardiac injury, and IL-6, specifically, shows promise in predicting readmission and mortality following cardiac surgery.

Surgical Atrial Fibrillation Ablation Improves Long-Term Survival: A Multicenter Analysis.

BACKGROUND: The Society of Thoracic Surgeons guidelines recommend surgical ablation (SA) at the time of concomitant mitral operations, aortic valve replacement, coronary artery bypass grafting (CABG), and aortic valve replacement plus CABG for patients in atrial fibrillation (AF). The goal of this analysis was to assess the influence of SA on long-term survival. METHODS: A retrospective analysis of 20,407 consecutive CABG or valve procedures from 2008 to 2015 among seven centers reporting to a prospectively maintained clinical registry was conducted. Patients undergoing operation with documented preoperative AF were included (n = 2,740). Patients receiving SA were compared with patients receiving no SA. The primary end point was all-cause mortality. Secondary end points included in-hospital morbidity and mortality. RESULTS: The frequency of SA was 23.1% (n = 634), and an increase was seen in the rate of SA over the study period (p < 0.001). Concomitant SA was performed in 16.2% of CABG, 30.6% of valve, and 24.3% of valve plus CABG procedures. A substantial improvement was found in unadjusted survival among patients undergoing SA (hazard ratio 0.54, 95% confidence interval: 0.42 to 0.70). Moreover, no differences were found in postoperative complications. SA did have longer bypass times (p < 0.001) but a shorter overall length of stay (p < 0.001). After risk adjustment, SA patients had an improved 5-year survival (hazard ratio 0.69, 95% confidence interval: 0.51 to 0.92), and the effect was observed across all operations. CONCLUSIONS: In a multicenter cohort of patients with AF, concomitant SA resulted in substantially improved long-term survival across patients who underwent CABG, valve, and valve plus CABG. These findings support current guidelines from The Society of Thoracic Surgeons that recommend broader application of concomitant SA.

Intensity of Glycemic Control Affects Long-Term Survival After Coronary Artery Bypass Graft Surgery.

BACKGROUND: A patient's hemoglobin (Hb) A1c level, regardless of diabetic status, is a measure of glycemic control. Studies have found it is an independent predictor of short-term death in patients undergoing coronary artery bypass grafting (CABG). In this study, we used preoperative HbA1c to assess whether levels are associated with short-term and long-term survival after CABG. METHODS: From a regional registry of consecutive cases, we identified 6,415 patients undergoing on-pump isolated CABG from 2008 to 2015 with documented preoperative HbA1c level. We defined four HbA1c groups: less than 5.7% (n = 1,713), 5.7% to 6.4% (n = 2,505), 6.5% to 8.0% (n = 1,377), and more than 8% (n = 820). Relationship to in-hospital outcomes and long-term survival was assessed. Outcome rates and hazard ratios were adjusted for patient and disease risk factors using multivariable logistic regression and Cox models. RESULTS: The study included 3,740 patients (58%) not diagnosed as having diabetes and 2,674 with diabetes. Prediabetes (HbA1c 5.7% to 6.4%) was documented in 52% (n = 1,933) of nondiabetic patients. Higher HbA1c values were associated with younger age, female sex, greater body mass index, more comorbid diseases, lower ejection fraction, more 3-vessel coronary disease, and recent myocardial infarction (p < 0.05 trend for all). After adjustment for patient risk, greater HbA1c values were not associated with higher rates of in-hospital death or morbidity. Long-term survival was significantly worse as HbA1c increased. Risk of death increased by 13% for every unit increase in HbA1c (adjusted hazard ratio, 1.13; 95% confidence interval, 1.07 to 1.19; p < 0.001). CONCLUSIONS: Preadmission glycemic control, as assessed by HbA1c, is predictive of long-term survival, with higher levels associated with poorer prognosis. Whether this risk can be modified by better glycemic control postoperatively remains to be determined.

sST2 as a novel biomarker for the prediction of in-hospital mortality after coronary artery bypass grafting.

Objectives: Soluble suppression of tumorigenicity 2 (sST2) biomarker is an emerging predictor of adverse clinical outcomes, but its prognostic value for in-hospital mortality after coronary artery bypass grafting (CABG) is not well understood. This study measured the association between operative sST2 levels and in-hospital mortality after CABG. Methods: A prospective cohort of 1560 CABG patients were analyzed from the Northern New England Cardiovascular Disease Study Group Biomarker Study. The primary outcome was in-hospital mortality after CABG surgery (n = 32). Results: After risk adjustment, patients in the third tercile of pre-, post- and pre-to-postoperative sST2 values experienced significantly greater odds of in-hospital death compared to patients in the first tercile of sST2 values. The addition of both postoperative and pre-to-postoperative sST2 biomarker significantly improved ability to predict in-hospital mortality status following CABG surgery, compared to using the EuroSCORE II mortality model alone, (c-statistic: 0.83 [95% CI: 0.75, 0.92], p value 0.0213) and (c-statistic: 0.83 [95% CI: 0.75, 0.92], p value 0.0215), respectively. Conclusion: sST2 values are associated with in-hospital mortality after CABG surgery and postoperative and pre-to-post operative sST2 values improve prediction. Our findings suggest that sST2 can be used as a biomarker to identify adult patients at greatest risk of in-hospital death after CABG surgery.

Comparative effectiveness of coronary artery bypass grafting versus percutaneous coronary intervention in a real-world Surgical Treatment for Ischemic Heart Failure trial population.

OBJECTIVE: There are no prospective randomized trial data to guide decisions on optimal revascularization strategies for patients with multivessel coronary artery disease and reduced ejection fraction. In this analysis, we describe the comparative effectiveness of coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) in this patient population. METHODS: A multicenter, retrospective analysis of all CABG (n = 18,292) and PCIs (n = 55,438) performed from 2004 to 2014 among 7 medical centers reporting to the Northern New England Cardiovascular Disease Study Group. After applying inclusion and exclusion criteria from the Surgical Treatment for Ischemic Heart Failure trial, there were 955 CABG and 718 PCI patients with an ejection fraction ≤ 35% and 2- or 3-vessel disease. Inverse probability weighting was used for risk adjustment. The primary end point was all-cause mortality. Secondary end points included rates of 30-day mortality, stroke, acute kidney injury, and incidence of repeat revascularization. RESULTS: The median duration of follow-up was 4.3 years (range, 1.59-6.71 years). CABG was associated with improved long-term survival compared with PCI after risk adjustment (hazard ratio, 0.59; 95% confidence interval, 0.50-0.71; P < .01). Although CABG and PCI had similar 30-day mortality rates (P = .14), CABG was associated with a higher frequency of stroke (P < .001) and acute kidney injury (P < .001), whereas PCI was associated with a higher incidence of repeat revascularization (P < .001). CONCLUSIONS: Among patients with reduced ejection fraction and multivessel disease, CABG was associated with improved long-term survival compared with PCI. CABG should be strongly considered in patients with ischemic cardiomyopathy and multivessel coronary disease.

Predictive Ability of Novel Cardiac Biomarkers ST2, Galectin-3, and NT-ProBNP Before Cardiac Surgery.

BACKGROUND: Current preoperative models use clinical risk factors alone in estimating risk of in-hospital mortality following cardiac surgery. However, novel biomarkers now exist to potentially improve preoperative prediction models. An assessment of Galectin-3, N-terminal pro b-type natriuretic peptide (NT-ProBNP), and soluble ST2 to improve the predictive ability of an existing prediction model of in-hospital mortality may improve our capacity to risk-stratify patients before surgery. METHODS AND RESULTS: We measured preoperative biomarkers in the NNECDSG (Northern New England Cardiovascular Disease Study Group), a prospective cohort of 1554 patients undergoing coronary artery bypass graft surgery. Exposures of interest were preoperative levels of galectin-3, NT-ProBNP, and ST2. In-hospital mortality and adverse events occurring after coronary artery bypass graft were the outcomes. After adjustment, NT-ProBNP and ST2 showed a statistically significant association with both their median and third tercile categories with NT-ProBNP odds ratios of 2.89 (95% confidence interval [CI]: 1.04-8.05) and 5.43 (95% CI: 1.21-24.44) and ST2 odds ratios of 3.96 (95% CI: 1.60-9.82) and 3.21 (95% CI: 1.17-8.80), respectively. The model receiver operating characteristic score of the base prediction model (0.80 [95% CI: 0.72-0.89]) varied significantly from the new multi-marker model (0.85 [95% CI: 0.79-0.91]). Compared with the Northern New England (NNE) model alone, the full prediction model with biomarkers NT-proBNP and ST2 shows significant improvement in model classification of in-hospital mortality. CONCLUSIONS: This study demonstrates a significant improvement of preoperative prediction of in-hospital mortality in patients undergoing coronary artery bypass graft and suggests that biomarkers can be used to identify patients at higher risk.

The Incidence and Consequence of Prosthesis-Patient Mismatch After Surgical Aortic Valve Replacement.

BACKGROUND: The goal of this study was to determine the relationship of prosthesis-patient mismatch (PPM) with long-term survival and to assess whether growing concern about PPM has resulted in a decreased incidence over time. METHODS: Using The Society of Thoracic Surgeons Adult Cardiac Surgery Database, we identified 59,779 patients ≥65 years old who underwent isolated surgical aortic valve replacement (AVR) between 2004 and 2014. The degree of PPM was calculated using literature-derived effective orifice areas for commonly used valves. Outcomes to 10 years were stratified by degree of PPM. RESULTS: The distribution of PPM was as follows: 35%, none (n = 21,053); 54%, moderate (n = 32,243); and 11%, severe (n = 6,483). Compared with patients with no PPM, patients with moderate or severe PPM had a significantly increased risk of readmission for heart failure (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.09 to 1.21; HR, 1.37; 95% CI, 1.26 to 1.48) and redo AVR (HR, 1.41; 95% CI, 1.13 to 1.77; HR, 2.68; 95% CI, 2.01 to 3.56) for moderate or severe PPM, respectively. Survival was significantly worse for any degree of PPM (moderate to none: HR, 1.08; 95% CI, 1.05 to 1.12; severe to none: HR, 1.32; 95% CI, 1.25 to 1.39), with 10-year adjusted survival rates of 46%, 43%, and 35% for none, moderate, and severe, respectively (p < 0.001). The incidence of severe PPM decreased by 55% over the study period, from 13.8% in 2004 to 6.2% in 2014. CONCLUSIONS: Any degree of PPM significantly decreased long-term survival and increased readmission rates for both heart failure and reoperation for AVR. Temporal trends show a significant decrease in the incidence of PPM over the past decade.

Coronary Revascularization With Single Versus Bilateral Mammary Arteries: Is It Time to Change?

BACKGROUND: Arterial conduits are preferred to venous conduits for coronary artery bypass grafting because of longer patency. A single internal mammary artery (SIMA) is used routinely. Bilateral internal mammary arteries (BIMA) are used less frequently. We sought to determine whether BIMA were superior to SIMA. METHODS: From our regional registry of consecutive open heart operations, we identified 47,984 patients who underwent isolated coronary artery bypass grafting from 1992 to 2014. Of the 1,482 BIMA patients, 1,297 were propensity matched to a cohort of SIMA patients. Short-term outcomes were compared using standard statistical techniques. Long-term survival was compared using Kaplan-Meier estimators and compared using a log-rank test. RESULTS: BIMA patients were younger and had fewer comorbid conditions than SIMA patients. After propensity weighting, BIMA and SIMA patients were well matched. There was no difference in in-hospital outcomes for BIMA versus SIMA patients for mortality (1.2% [n = 15] vs 0.8% [n = 10], p = 0.315), stroke (0.7% [n = 9] vs 0.7% [n = 9), p = 1.000), bleeding (2.2% [n = 28] vs 2.8% [n = 36], p = 0.311), or mediastinitis (0.8% [n = 10] vs 0.9% [n = 12], p = 0.667). The median follow-up was 12 years. Survival was better for BIMA than SIMA (adjusted hazard ratio, 0.79; 95% confidence interval, 0.69 to 0.91; p < 0.001). Survival curves began to separate after 5 years. At 15 years, the absolute difference in survival was 8.4%. CONCLUSIONS: In a large regional experience, BIMA is associated with no upfront risk of adverse events and improved long-term survival compared with SIMA. Our results indicate that BIMA conduits should be considered more frequently during coronary artery bypass grafting due to their demonstrated survival advantage.

Should Diabetes Be a Contraindication to Bilateral Internal Mammary Artery Grafting?

BACKGROUND: This study evaluates the influence of bilateral internal mammary artery (BIMA) versus single internal mammary artery (SIMA) grafting on postoperative morbidity and long-term survival among diabetic patients undergoing coronary artery bypass grafting (CABG). METHODS: A multicenter, retrospective analysis of 47,984 consecutive CABGs performed from 1992 to 2014 at 7 medical centers was conducted. Among the study population, 1,482 CABGs with BIMA were identified, and 1,297 BIMA patients were propensity-matched to 1,297 SIMA patients. The study cohort for this analysis, drawn from matched data, included 430 diabetic patients: 217 SIMA and 213 BIMA. The primary endpoint was long-term survival. Secondary endpoints included postoperative morbidity, length of stay, and in-hospital mortality. RESULTS: The median duration of follow-up was 9.3 (range, 4.3 to 13.9) years. Among propensity-matched diabetic patients, there was no significant difference in age, body mass index, or major baseline comorbidities. The groups were also well matched on the number of diseased coronary arteries and number of distal anastomoses performed. There was no difference in the rate of mediastinitis or sternal dehiscence (p = 0.503) or in-hospital mortality (p = 0.758) between groups. Both groups had a similar median length of stay of 5 (range, 4 to 7) days. Diabetic patients who received a BIMA had significantly improved long-term survival when compared with SIMA patients (hazard ratio 0.75 [95% confidence interval 0.57 to 0.98], p = 0.034). CONCLUSIONS: Among diabetics undergoing CABG, use of BIMA grafting does not result in increased in-hospital morbidity or mortality and confers a long-term survival advantage when compared with SIMA grafting. Thus, diabetic patients should be considered for BIMA grafting more frequently.

Does Use of Bilateral Internal Mammary Artery Grafting Reduce Long-Term Risk of Repeat Coronary Revascularization? A Multicenter Analysis.

BACKGROUND: Although previous studies have demonstrated that patients receiving bilateral internal mammary artery (BIMA) conduits during coronary artery bypass grafting have better long-term survival than those receiving a single internal mammary artery (SIMA), data on risk of repeat revascularization are more limited. In this analysis, we compare the timing, frequency, and type of repeat coronary revascularization among patients receiving BIMA and SIMA. METHODS: We conducted a multicenter, retrospective analysis of 47 984 consecutive coronary artery bypass grafting surgeries performed from 1992 to 2014 among 7 medical centers reporting to a prospectively maintained clinical registry. Among the study population, 1482 coronary artery bypass grafting surgeries with BIMA were identified, and 1297 patients receiving BIMA were propensity-matched to 1297 patients receiving SIMA. The primary end point was freedom from repeat coronary revascularization. RESULTS: The median duration of follow-up was 13.2 (IQR, 7.4-17.7) years. Patients were well matched by age, body mass index, major comorbidities, and cardiac function. There was a higher freedom from repeat revascularization among patients receiving BIMA than among patients receiving SIMA (hazard ratio [HR], 0.78 [95% CI, 0.65-0.94]; P=0.009). Among the matched cohort, 19.4% (n=252) of patients receiving SIMA underwent repeat revascularization, whereas this frequency was 15.1% (n=196) among patients receiving BIMA (P=0.004). The majority of repeat revascularization procedures were percutaneous coronary interventions (94.2%), and this did not differ between groups (P=0.274). Groups also did not differ in the ratio of native versus graft vessel percutaneous coronary intervention (P=0.899), or regarding percutaneous coronary intervention target vessels; the most common targets in both groups were the right coronary (P=0.133) and circumflex arteries (P=0.093). In comparison with SIMA, BIMA grafting was associated with a reduction in all-cause mortality at 12 years of follow-up (HR, 0.79 [95% CI, 0.69-0.91]; P=0.001), and there was no difference in in-hospital morbidity. CONCLUSIONS: BIMA grafting was associated with a reduced risk of repeat revascularization and an improvement in long-term survival and should be considered more frequently during coronary artery bypass grafting.

National Trends and Geographic Variation in Bilateral Internal Mammary Artery Use in the United States.

BACKGROUND: The goal of this study was to characterize the adoption rate and regional variation in bilateral internal mammary artery (BIMA) use during coronary artery bypass grafting (CABG) in the United States. METHODS: Observational study of 100% sample of fee-for-service Medicare beneficiaries aged 65 years or older, continuously enrolled in Parts A and B from 2009 to 2014 (n = 162,860,439). Rates of beneficiaries receiving a BIMA versus single internal mammary artery (SIMA) during CABG are expressed per 1,000 beneficiaries and aggregated by Hospital Referral Region (HRR). An HRR is a validated unit for quantifying regional variation in health care. RESULTS: The absolute national rate of BIMA use declined during the study period from 0.21 claims per 1,000 beneficiaries in 2009 to 0.13 in 2014 (p < 0.001). When indexed to overall CABG volume, no change was seen in the frequency of BIMA use over time (p = 0.883). SIMA use ranged from 1.3 to 8.5 claims per 1,000 Medicare beneficiaries, whereas BIMA use ranged from 0 to 1.5 (p < 0.001). A significant correlation was found between regional volume of SIMA use and likelihood of BIMA use (correlation coefficient 0.673, p < 0.001). Although both SIMA and BIMA use correlated with regional volume of diagnostic cardiac catheterization, the correlation was stronger for SIMA use (correlation coefficient 0.962 versus 0.682, p < 0.001). CONCLUSIONS: Over the past 5 years, no growth was seen in BIMA use among Medicare beneficiaries, and the frequency of BIMA use during CABG remained low. There was significant regional variation in BIMA use, however, which demonstrates opportunity for continued growth of BIMA grafting.

Postoperative myocardial infarction in acute type A aortic dissection: A report from the International Registry of Acute Aortic Dissection.

OBJECTIVE: Postoperative myocardial infarction remains a serious complication in cardiac surgery. The incidence and impact of this condition in acute type A aortic dissection are poorly understood. METHODS: A total of 1445 patients with acute type A aortic dissection who underwent surgery were enrolled in the International Registry of Acute Aortic Dissection from 1996 to 2013. Individuals with preoperative myocardial infarction at hospital presentation and a history of myocardial infarction were excluded. Patients with postoperative myocardial infarction (n = 38, 2.6%) were compared with those without postoperative myocardial infarction (n = 1407, 97.4%). RESULTS: The postoperative myocardial infarction group was more often of white race (100% vs 90%, P = .043) with bicuspid aortic valve (15.6% vs 4.5%, P = .015). Imaging demonstrated more aortic root involvement (75.8% vs 49.5%, P = .003), pericardial effusion (65.5% vs 44.1%, P = .022), and coronary artery compromise (27.3% vs 10.2%, P = .022). Patients with postoperative myocardial infarction were more frequently hypotensive or in shock during surgery (42.9% vs 25.5%, P = .021). Patients with postoperative myocardial infarction were more likely to have undergone root replacement (54.5% vs 33.3%, P = .011), coronary artery bypass grafting (28.6% vs 7.4%, P < .001), or aortic valve replacement (40.0% vs 23.8%, P = .027), and less likely to have had complete arch replacement (2.8% vs 14.0%, P = .050). Median circulatory arrest time was higher in postoperative myocardial infarction (60 vs 38 minutes, P = .024). In-hospital mortality (57.9% vs 16.3%, P < .001) and Kaplan-Meier estimates of 5-year mortality (P = .007) were distinctly higher in postoperative myocardial infarction. CONCLUSIONS: Postoperative myocardial infarction is a devastating complication of type A aortic dissection repair. It is associated with bicuspid aortic valve, root involvement, pericardial effusion, and extent of surgical repair. Patients with postoperative myocardial infarction have higher serious postoperative complications, in-hospital mortality, and 5-year mortality rates than those without postoperative myocardial infarction.

Impact of perioperative acute kidney injury as a severity index for thirty-day readmission after cardiac surgery.

BACKGROUND: Of patients undergoing cardiac surgery in the United States, 15% to 20% are re-hospitalized within 30 days. Current models to predict readmission have not evaluated the association between severity of postoperative acute kidney injury (AKI) and 30-day readmissions. METHODS: We collected data from 2,209 consecutive patients who underwent either coronary artery bypass or valve surgery at 7 member hospitals of the Northern New England Cardiovascular Disease Study Group Cardiac Surgery Registry between July 2008 and December 2010. Administrative data at each hospital were searched to identify all patients readmitted to the index hospital within 30 days of discharge. We defined AKI stages by the AKI Network definition of 0.3 or 50% increase (stage 1), twofold increase (stage 2), and a threefold or 0.5 increase if the baseline serum creatinine was at least 4.0 (mg/dL) or new dialysis (stage 3). We evaluate the association between stages of AKI and 30-day readmission using multivariate logistic regression. RESULTS: There were 260 patients readmitted within 30 days (12.1%). The median time to readmission was 9 (interquartile range, 4 to 16) days. Patients not developing AKI after cardiac surgery had a 30-day readmission rate of 9.3% compared with patients developing AKI stage 1 (16.1%), AKI stage 2 (21.8%), and AKI stage 3 (28.6%, p < 0.001). Adjusted odds ratios for AKI stage 1 (1.81; 1.35, 2.44), stage 2 (2.39; 1.38, 4.14), and stage 3 (3.47; 1.85 to 6.50). Models to predict readmission were significantly improved with the addition of AKI stage (c-statistic 0.65, p = 0.001) and net reclassification rate of 14.6% (95% confidence interval: 5.05% to 24.14%, p = 0.003). CONCLUSIONS: In addition to more traditional patient characteristics, the severity of postoperative AKI should be used when assessing a patient's risk for readmission.

Effect of preoperative pulmonary hypertension on outcomes in patients with severe aortic stenosis following surgical aortic valve replacement.

Pulmonary hypertension (PH) is prevalent in patients with aortic stenosis (AS); however, previous studies have demonstrated inconsistent results regarding the association of PH with adverse outcomes after aortic valve replacement (AVR). The goal of this study was to evaluate the effects of preoperative PH on outcomes after AVR. We performed a regional prospective cohort study using the Northern New England Cardiovascular Disease Study Group database to identify 1,116 consecutive patients from 2005 to 2010 who underwent AVR ± coronary artery bypass grafting for severe AS with a preoperative assessment of pulmonary pressures by right-sided cardiac catheterization. PH was defined as a mean pulmonary artery pressure of ≥25 mm Hg, with severity based on the pulmonary artery systolic pressure-mild, 35 to 44 mm Hg; moderate, 45 to 59 mm Hg; and severe, ≥60 mm Hg. We found that PH was present in 536 patients (48%). Postoperative acute kidney injury, low-output heart failure, and in-hospital mortality increased with worsening severity of PH. In multivariate logistic regression, severe PH was independently associated with postoperative acute kidney injury (adjusted odds ratio 4.1, 95% confidence interval [CI] 1.7 to 10, p = 0.002) and in-hospital mortality (adjusted odds ratio 6.9, 95% CI 2.5 to 19.1, p <0.001). There was a significant association between PH and decreased 5-year survival (adjusted log-rank p value = 0.006), with severe PH being associated with the poorest survival (adjusted hazard ratio 2.4, 95% CI 1.3 to 4.2, p = 0.003). In conclusion, severe PH in patients with severe AS is associated with increased rates of in-hospital adverse events and decreased 5-year survival after AVR.

Preoperative white blood cell count and risk of 30-day readmission after cardiac surgery.

Approximately 1 in 5 patients undergoing cardiac surgery are readmitted within 30 days of discharge. Among the primary causes of readmission are infection and disease states susceptible to the inflammatory cascade, such as diabetes, chronic obstructive pulmonary disease, and gastrointestinal complications. Currently, it is not known if a patient's baseline inflammatory state measured by crude white blood cell (WBC) counts could predict 30-day readmission. We collected data from 2,176 consecutive patients who underwent cardiac surgery at seven hospitals. Patient readmission data was abstracted from each hospital. The independent association with preoperative WBC count was determined using logistic regression. There were 259 patients readmitted within 30 days, with a median time of readmission of 9 days (IQR 4-16). Patients with elevated WBC count at baseline (10,000-12,000 and >12,000 mm(3)) had higher 30-day readmission than those with lower levels of WBC count prior to surgery (15% and 18% compared to 10%-12%, P = 0.037). Adjusted odds ratios were 1.42 (0.86, 2.34) for WBC counts 10,000-12,000 and 1.81 (1.03, 3.17) for WBC count > 12,000. We conclude that WBC count measured prior to cardiac surgery as a measure of the patient's inflammatory state could aid clinicians and continuity of care management teams in identifying patients at heightened risk of 30-day readmission after discharge from cardiac surgery.

Impact of preoperative left ventricular ejection fraction on long-term survival after aortic valve replacement for aortic stenosis.

BACKGROUND: The survival of patients who undergo aortic valve replacement (AVR) for severe aortic stenosis with reduced preoperative ejection fractions (EFs) is not well described in the literature. METHODS AND RESULTS: Patients undergoing AVR for severe aortic stenosis were analyzed using the Northern New England Cardiovascular Disease Study Group surgical registry. Patients were stratified by preoperative EF (≥50%, 40%-49%, and <40%) and concomitant coronary artery bypass grafting. Crude and adjusted survival across strata of EF was estimated for patients up to 8 years beyond their index admission. A total of 5277 patients underwent AVR for severe aortic stenosis between 1992 and 2008. There were 727 (14%) patients with preoperative EF <40%. Preoperative EF had minimal effect on postoperative morbidity. There was no difference in 30-day mortality across EF strata among the isolated AVR cohort. Preserved EF conferred 30-day survival benefit among the AVR+coronary artery bypass grafting population (EF≥50%, 96%; EF<40%, 91%; P=0.003). Patients with preserved EF had significantly improved 6-month and 8-year survival compared with their reduced EF counterparts. CONCLUSIONS: Survival after AVR or AVR+coronary artery bypass grafting was most favorable among patients with preoperative preserved EF. However, patients with mild to moderately depressed EF experienced a substantial survival benefit compared with the natural history of medically treated patients. Furthermore, minor reductions of EF carried equivalent increased risk to those with more compromised function suggesting patients are best served when an AVR is performed before even minor reductions in myocardial function.