Moderate Aortic Stenosis in Patients With Heart Failure.

BACKGROUND AND OBJECTIVES: Moderate aortic stenosis (AS) confers a surprisingly adverse prognosis, approaching that of severe AS. The objective of this study was to describe the clinical course of patients with moderate AS with evidence of concomitant heart failure manifesting as elevated brain natriuretic peptide (BNP) levels. METHODS: This is a single-center, retrospective cohort study of 332 patients with elevated BNP. 165 patients with moderate AS were compared with 167 controls with none-mild AS. The Median follow-up duration was 3.85 years. The primary outcome was a composite endpoint of all-cause hospitalizations and all-cause mortality. RESULTS: BNP levels were 530 and 515 pg/mL in the study and the control groups, respectively. Moderate AS had significantly higher rates of primary composite endpoint in both univariate analysis (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.14-1.97; p=0.004) and adjusted analysis (HR, 1.45; 95% CI, 1.05-2.01; p=0.02). Moderate AS had 1.41 (95% CI, 1.18-1.69; p<0.001) times more all-cause hospitalization per patient-year of follow-up compared to controls in the univariate model. After adjustment for significant covariates, moderate AS remained an independent predictor of all-cause hospitalizations (incidence rate ratio [IRR], 1.45; 95% CI, 1.18-1.79; p=0.005). Furthermore, moderate AS was significantly associated with higher all-cause hospitalization rates in both heart failure with reduced ejection fraction (IRR, 1.33; 95% CI, 1.02-1.75; p=0.038) and heart failure with preserved ejection fraction [IRR], 1.31; 95% CI, 1.03-1.67; p=0.026). CONCLUSIONS: Moderate AS in conjunction with elevated BNP portends a significantly worse prognosis than those without moderate AS and should be followed closely.

Ultrasound-Guided Continuous Bilateral Erector Spinae Plane Blocks Are Associated with Reduced Opioid Consumption and Length of Stay for Open Cardiac Surgery: A Retrospective Cohort Study.

This study tested the hypothesis that continuous bilateral erector spinae plane blocks placed preoperatively would reduce opioid consumption and improve outcomes compared with standard practice in open cardiac surgery patients. Patients who received bilateral continuous erector spinae plane blocks for primary open coronary bypass, aortic valve, or ascending aortic surgery were compared to a historical control group. Patients in the block group received a 0.5% ropivacaine bolus preoperatively followed by a 0.2% ropivacaine infusion begun postoperatively. No other changes were made to the perioperative care protocol. The primary outcome was opioid consumption. Secondary outcomes were time to extubation and length of stay. Twenty-eight patients received continuous erector spinae plane blocks and fifty patients served as historic controls. Patients who received blocks consumed less opioids, expressed as oral morphine equivalents, both intraoperatively (34 ± 17 vs. 224 ± 125 mg) and during their hospitalization (224 ± 108 vs. 461 ± 185 mg). Patients who received blocks had shorter times to extubation (126 ± 87 vs. 257 ± 188 min) and lengths of stay in the intensive care unit (35 ± 17 vs. 58 ± 42 h) and hospital (5.6 ± 1.6 vs. 7.7 ± 4.6 days). Continuous erector spinae plane blocks placed prior to open cardiac surgical procedures reduced opioid consumption, time to extubation, and length of stay compared to a standard perioperative pathway.

Rapid diagnostic testing as an indicator of malaria prevalence in Rorya District, Tanzania.

BACKGROUND: Rapid Diagnostic Testing (RDT), a point-of-care, qualitative test for Plasmodium antigen, has been a catalyst in the diagnosis of patients in malaria-endemic regions. While blood-smear microscopy remains the gold standard, RDT allows for swift diagnosis in resource-poor settings. Our study sought to utilize RDT to quantify local malaria prevalence in the Rorya district of Tanzania. MATERIALS AND METHODS: Two field clinics were established and 1,032 patients were screened. Those that described malaria symptoms were tested via RDT. The percentage of positive tests was compared to national data from the World Health Organization's 2019 World Malaria report and the President's Malaria Initiative Report for Tanzania. Intake data (sex, age, heart rate (HR), and temperature) were compared between the malaria-positive and malaria-negative groups. RESULTS: 772 patients received RDT of whom 487 tested positive. There was a statistically significant difference in the percentage of positive patients between the two sites (52.0% vs 38.2%). Sixty percent of malaria-positives were female and the median age of this group was 10 yrs (range 5-15 yrs). Intake data showed a notable difference in median heart rates between malaria-positive and malaria-negative persons, 84.0 (72-100) and 72.0 (74-84) beats per minute (bpm), respectively. CONCLUSIONS: The prevalence of malaria in Rorya was significantly higher than the reported Tanzanian average. Additionally, children were at a statistically higher risk of contracting malaria. Our data indicates that RDT offers enhanced insight into the local malarial burden that may be valuable to (governmental) health providers for the disbursement of resources in malaria-endemic regions.

Transcatheter Aortic Valve Replacement and Left Ventricular Geometry: Survival and Gender Differences.

BACKGROUND: The aim of this study was to examine the relationship between baseline left ventricular (LV) geometry and outcomes after transcatheter aortic valve replacement (TAVR). METHODS: Patients undergoing TAVR (n = 206) had baseline LV geometry classified as (1) concentric hypertrophy, (2) eccentric hypertrophy, (3) concentric remodeling, or (4) normal. Descriptive statistics, Kaplan-Meier time-to-event analysis, and Cox regression were performed. RESULTS: Distribution of baseline LV geometry differed between male and female patients (χ2 = 16.83, P = .001) but not at 1 month (χ2 = 2.56, P = .47) or 1 year (χ2 = 5.68, P = .13). After TAVR, a majority of patients with concentric hypertrophy evolved to concentric remodeling. Survival differed across LV geometry groups at 1 year (χ2[3] = 8.108, P = .044, log-rank test) and at 6.5 years (χ2[3] = 9.023, P = .029, log-rank test). Compared with patients with concentric hypertrophy, patients with normal geometry (hazard ratio, 2.25; 95% CI, 1.12-4.54; P = .023) and concentric remodeling (hazard ratio, 1.89; 95% CI, 1.12-3.17; P = .016) had higher rates of all-cause mortality. CONCLUSIONS: Baseline concentric hypertrophy confers a survival advantage after TAVR. Although baseline patterns of LV geometry appear gender specific (with women demonstrating more concentric hypertrophy), this difference resolves after TAVR.

Fifty Percent Reduction in Narcotic Use After Minimally Invasive Cardiac Surgery Using Liposomal Bupivacaine.

OBJECTIVE: Minimally invasive cardiac surgery via a right minithoracotomy (RMT) is a common approach to different valve pathologies, tumor resection, and atrial septal defect (ASD) closure. We studied intraoperative field block using liposomal bupivacaine (LB) in these operations. METHODS: Consecutive 171 minimally invasive RMTs (fourth intercostal space) were studied, and patients in cardiogenic or septic shock, intravenous drug abuse, and those re-explored were excluded (n = 12). An early cohort was treated with standard postoperative analgesia while another underwent intraoperative field block with LB immediately after incision. We compared postoperative pain level, narcotic utilization (morphine milligram equivalent), and intensive care unit (ICU) and hospital length of stay. RESULTS: The procedures included 48 isolated mitral valve replacements (MVR); 2 MVR with other procedures; 93 mitral valve repairs (MVRr); 9 MVRr with other procedures; 4 isolated tricuspid valve repairs; 2 myxoma resections; 1 ASD closure. There were 13 patients in the non-LB group and 146 patients in the LB group. Use of LB decreased mean postoperative narcotic utilization by 50% (P = 0.003). The LB group had lower pain levels on postoperative day 1 (P = 0.039), which continued through postoperative day 5 (P = 0.030). We found no difference in ICU or hospital length of stay between groups. There were no complications from LB field block. CONCLUSIONS: LB field block decreases postoperative pain and narcotic utilization after cardiac surgery via a RMT, but it does not reduce length of stay. The technique is safe and should be considered in all patients undergoing RMT cardiac surgery.

Changes in mechanical dyssynchrony in severe aortic stenosis patients undergoing transcatheter aortic valve replacement.

INTRODUCTION: Aortic stenosis (AS) imposes a significant afterload on the left ventricle, but regional manifestations of the overall load may not be uniform, leading to mechanical dyssynchrony. Accordingly, we evaluated the prevalence of dyssynchrony in patients with severe AS at baseline as well as changes after transfemoral aortic valve replacement (TAVR). METHODS: This study is a retrospective analysis of 225 patients in sinus rhythm who underwent TAVR for severe AS, in whom inter-ventricular and intra-ventricular dyssynchrony were measured at baseline, discharge, 1 month, and 1 year. Inter-ventricular dyssynchrony was defined as the difference between left and right ventricular pre-ejection intervals; intra-ventricular dyssynchrony was defined as the difference between time to peak systolic velocity of the basal septal and lateral segments. Patients were further stratified into those with QRS <120 ms or >120 ms. RESULTS: At baseline, a quarter of patients met the criterion for significant inter-ventricular dyssynchrony, and a third had evidence of intra-ventricular dyssynchrony. Both decreased after TAVR although only the intra-ventricular dyssynchrony reached statistical significance. The interplay between QRS duration and changes in inter- and intra-ventricular dyssynchrony are also explored. CONCLUSIONS: In patients with severe AS, there was evidence of mechanical dyssynchrony that is improved post-TAVR. Whether dyssynchrony is clinically and prognostically significant, and if it represents a potential target for additional therapy remains to be studied.

Cardiac magnetic resonance tissue tracking in right ventricle: Feasibility and normal values.

PURPOSE: To investigate right ventricular (RV) strain in patients without identified cardiac pathology using cardiac magnetic resonance tissue tracking (CMR TT). METHODS: A total of 50 consecutive patients with no identified cardiac pathology were analyzed. RV longitudinal and circumferential strain was assessed by CMR TT. The age range was 4-81years with a median of 32years (interquartile range, 15 to 56years). RESULTS: Analysis time per patient was <5min. The peak longitudinal strain (Ell) was -22.11±3.51%. The peak circumferential strains (Ecc) for global, basal, mid-cavity and apical segments were as follows: -11.69±2.25%, -11.00±2.45%, -11.17±3.36%, -12.90±3.34%. There were significant gender differences in peak Ecc at the base (P=0.04) and the mid-cavity (P=0.03) with greater deformation in females than in males. On Bland-Altman analysis, peak Ell (mean bias, 0.22±1.67; 95% CI -3.05 to 3.49) and mid-cavity Ecc (mean bias, 0.036±1.75; 95% CI, -3.39 to 3.47) had the best intra-observer agreement and inter-observer agreement, respectively. CONCLUSIONS: RV longitudinal and circumferential strains can be quickly assessed with good intra-observer and inter-observer variability using TT.

Diagnostic Performance of Treadmill Exercise Cardiac Magnetic Resonance: The Prospective, Multicenter Exercise CMR's Accuracy for Cardiovascular Stress Testing (EXACT) Trial.

BACKGROUND: Stress cardiac magnetic resonance (CMR) has typically involved pharmacologic agents. Treadmill CMR has shown utility in single-center studies but has not undergone multicenter evaluation. METHODS AND RESULTS: Patients referred for treadmill stress nuclear imaging (SPECT) were prospectively enrolled across 4 centers. After rest (99m)Tc SPECT, patients underwent resting cine CMR. In-room stress was then performed using an MR-compatible treadmill with continuous 12-lead electrocardiogram monitoring. At peak stress, (99m)Tc was injected, and patients rapidly returned to the MR scanner isocenter for real-time, free-breathing stress cine and perfusion imaging. After recovery, cine and rest perfusion followed by late gadolinium enhancement acquisitions concluded CMR imaging. Stress SPECT was then acquired in adjacent nuclear laboratories. A subset of patients not referred for invasive coronary angiography within 2 weeks of stress underwent coronary computed tomography angiography. Angiographic data available in 94 patients showed sensitivity of 79%, specificity of 99% for exercise CMR with positive predictive value of 92% and negative predictive value of 96%. Agreement between treadmill stress CMR and angiography was strong (κ=0.82), and moderate between SPECT and angiography (κ=0.46) and CMR versus SPECT (κ=0.48). CONCLUSIONS: The multicenter EXACT trial indicates excellent diagnostic value of treadmill stress CMR in typical patients referred for exercise SPECT.

The Relationship Among Heart Failure Disease Management, Quality of Care, and Hospitalizations.

Heart failure (HF) affects 5.1 million adult patients, accounting for over 1 million hospitalizations, 1.8 million office visits, and nearly 680,000 emergency department visits annually. HF hospitalizations have been incorporated into a national measure of hospital and provider quality, with associated financial penalties based on the 30-day readmission rate after an index hospitalization for HF. However, it is not clear whether the number of HF-related hospitalizations or 30-day readmissions is consistently related to quality of care. The relationships between various measures of HF care quality and hospitalization rates were evaluated by performing a cohort study of an HF disease management program in a clinical practice setting. Following the statistical analyses assessing outcomes and survival, the conclusion was that an HF disease management program in clinical practice associated with improved utilization of evidence-based medical and device therapies tends to improve ejection fraction and survival, and reduce sex and race disparities, but not with an associated reduction in hospitalizations or total hospital days.

A pilot study of target weight guided treatment in acute heart failure using ultrafiltration or usual care: effect on sodium removal.

BACKGROUND AND OBJECTIVES: In the Ultrafiltration versus Intravenous Diuretics for Patients Hospitalized for Acute Decompensated Heart Failure trial, ultrafiltration (UF) removed volume more effectively than usual care (UC). Hypothetically, UF may be superior to UC due to increased sodium (Na) removal and less neurohormonal activation. We compared UF and UC in a randomized pilot trial of target weight guided therapy for acute decompensated heart failure (ADHF). SUBJECTS AND METHODS: Sixteen patients with ADHF were enrolled and target weights established prospectively, prior to randomization to UC or UF. UF patients did not receive diuretics and UC patients were all treated with a continuous furosemide drip. All urine and ultrafiltrate were collected and Na concentrations measured. RESULTS: Similar volumes were removed in UC and UF groups (110105 mL and 107415 mL, respectively) and the UF group also produced 45325 mL of urine. Na concentration was 138±6 meq/L in the ultrafiltrate, 85±73 meq/L in the UC group's urine, and 26±23 meq/L in the UF group's urine. Given the relevant associated volumes, total meq of the Na removed was similar (1168 in UC vs. 1216 in UF). The UF group produced isotonic ultrafiltrate and a higher volume of dilute urine than anticipated. CONCLUSION: In a randomized pilot study of target weight guided therapy with UC or UF for ADHF, there were no differences in total volumes or Na removed, and lengths of hospital stays were similar. Isotonic fluid loss by UF was accompanied by the production of very dilute urine.

A combined anatomic and electrophysiologic substrate based approach for sudden cardiac death risk stratification.

BACKGROUND: Although left ventricular ejection fraction (LVEF) is the primary determinant for sudden cardiac death (SCD) risk stratification, in isolation, LVEF is a sub-optimal risk stratifier. We assessed whether a multi-marker strategy would provide more robust SCD risk stratification than LVEF alone. METHODS: We collected patient-level data (n = 3355) from 6 studies assessing the prognostic utility of microvolt T-wave alternans (MTWA) testing. Two thirds of the group was used for derivation (n = 2242) and one-third for validation (n = 1113). The discriminative capacity of the multivariable model was assessed using the area under the receiver-operating characteristic curve (c-index). The primary endpoint was SCD at 24 months. RESULTS: In the derivation cohort, 59 patients experienced SCD by 24 months. Stepwise selection suggested that a model based on 3 parameters (LVEF, coronary artery disease and MTWA status) provided optimal SCD risk prediction. In the derivation cohort, the c-index of the model was 0.817, which was significantly better than LVEF used as a single variable (0.637, P < .001). In the validation cohort, 36 patients experienced SCD by 24 months. The c-index of the model for predicting the primary endpoint was again significantly better than LVEF alone (0.774 vs 0.671, P = .020). CONCLUSIONS: A multivariable model based on presence of coronary artery disease, LVEF and MTWA status provides significantly more robust SCD risk prediction than LVEF as a single risk marker. These findings suggest that multi-marker strategies based on different aspects of the electro-anatomic substrate may be capable of improving primary prevention implantable cardioverter-defibrillator treatment algorithms.

Ultrafiltration in heart failure with preserved ejection fraction: comparison with systolic heart failure patients.

BACKGROUND: Ultrafiltration (UF) is a widely used technology for inpatient management of acute decompensated heart failure in patients with volume overload. However, the safety and efficacy of UF in patients with heart failure and preserved left ventricular ejection fraction (heart failure with preserved ejection fraction [HFPEF]) need further clarification. We hypothesized that UF could be used in this population with outcomes similar to acute decompensated heart failure patients with low left ventricular ejection fraction (HFLEF). METHODS AND RESULTS: Prospective evaluation was performed on 2 patient cohorts admitted to a single institution for acute decompensated heart failure and treated with UF: HFLEF (left ventricular ejection fraction ≤ 40%; n=87) and HFPEF (left ventricular ejection fraction >40%; n=97). Selected demographic and clinical data were compared, including clinical and serological information, as well as in-hospital and 90-day postdischarge mortality. HFPEF patients were more likely to be women, have higher blood pressures, and less likely to have ischemic heart disease. There were no significant differences in total weight loss (7.7% in HFLEF and 7.0% in HFPEF), electrolyte and renal disturbances, or in-hospital mortality (3.4% in HFLEF and 3.3% in HFPEF) between the 2 groups. Mortality at 90 days tended to be greater in HFLEF (24.1%) than in HFPEF (15.5%). CONCLUSIONS: Therapeutic responses in patients with HFPEF meeting current indication for UF are similar to those with HFLEF. Larger studies are warranted to better characterize acute heart failure management with UF in this population.

Effect of automated, point-of-care electronic medical record screening for appropriate implantable device use in heart failure patients.

The authors evaluated the effects of an electronic health record (EHR)-based real-time screening of outpatients for potential defibrillator therapy on practice metrics. Based on ejection fraction (EF) ≤ 35% and absence of a defibrillator, the physicians were prompted for an action: electrophysiology consultation, EF evaluation, or "not indicated." Although the number of patients screened remained stable at nearly 6000 per month, consultations and echocardiograms peaked early but returned to a low steady state by 10 months. The number of actual device implants did not increase appreciably as a result of this program. Implementation of a real-time EHR screening algorithm in a busy clinical practice is feasible and generally unobtrusive, without an effect on productivity. Its impact on adherence to guideline-based recommendation is not notable in this case. The number of resulting actionable items declines dramatically and plateaus by 10 months, affording an opportunity to cycle, rather than add, other screening protocols.

Clinical utility of microvolt T-wave alternans testing in identifying patients at high or low risk of sudden cardiac death.

BACKGROUND: Previous studies have demonstrated that microvolt T-wave alternans (MTWA) testing is a robust predictor of ventricular tachyarrhythmias and sudden cardiac death (SCD) in at-risk patients. However, recent studies have suggested that MTWA testing is not as good a predictor of "appropriate" implantable cardioverter-defibrillator (ICD) therapy as it is a predictor of SCD in patients without ICDs. OBJECTIVE: To evaluate the utility of MTWA testing for SCD risk stratification in patients without ICDs. METHODS: Patient-level data were obtained from 5 prospective studies of MTWA testing in patients with no history of ventricular arrhythmia or SCD. In these studies, ICDs were implanted in only a minority of patients and patients with ICDs were excluded from the analysis. We conducted a pooled analysis and examined the 2-year risk for SCD based on the MTWA test result. RESULTS: The pooled cohort included 2883 patients. MTWA testing was positive in 856 (30%), negative in 1627 (56%), and indeterminate in 400 (14%) patients. Among patients with a left ventricular ejection fraction (LVEF) of ≤35%, annual SCD event rates were 4.0%, 0.9%, and 4.6% among groups with MTWA positive, negative, and indeterminate test results. The SCD rate was significantly lower among patients with a negative MTWA test result than in patients with either positive or indeterminate MTWA test results (P <.001 for both comparisons). In patients with an LVEF of >35%, annual SCD event rates were 3.0%, 0.3%, and 0.3% among the groups with MTWA positive, negative, and indeterminate test results. The SCD rate associated with a positive MTWA test result was significantly higher than that associated with either negative (P <.001) or indeterminate MTWA test results (P = .003). CONCLUSIONS: In patients without ICDs, MTWA testing is a powerful predictor of SCD. Among patients with an LVEF of ≤35%, a negative MTWA test result is associated with a low risk for SCD. Conversely, among patients with an LVEF of >35%, a positive MTWA test result identifies patients at significantly heightened SCD risk. These findings may have important implications for refining primary prevention ICD treatment algorithms.

Fragmented QRS and mortality risk in patients with left ventricular dysfunction.

BACKGROUND: Fragmented QRS (fQRS) has been shown to predict cardiac events in select patient populations. Whether fQRS improves patient selection for primary prevention patients eligible for implantable cardioverter-defibrillator (ICD) therapy remains unknown. METHODS AND RESULTS: In a prospective, multisite cohort of 842 patients with left ventricular dysfunction (ejection fraction < or =35%) representing both ischemic and nonischemic etiology, the presence of fQRS on ECG was assessed using standardized criteria. The association between fQRS and all-cause and arrhythmic mortality was evaluated overall and stratified by ICD status using multivariable Cox regression models, adjusted for demographic, clinical, and treatment variables. Fragmented QRS was present in 274 (32.5%) patients, and there were 191 (22.7%) deaths during a mean follow-up of 40+/-17 months. Rates of all-cause mortality did not differ between the fQRS+ (19.7%) and fQRS- (24.1%) groups; adjusted hazard ratio, 0.88; 95% confidence interval, 0.63-1.22; P=0.43. Additionally, rates of arrhythmic mortality were similar between the fQRS+ (9.9%) and fQRS- (12.7%) groups: adjusted hazard ratio, 0.77; 95% confidence interval, 0.49-1.31; P=0.38. Subgroup analyses found no association between fQRS and mortality when the cohort was further stratified by ICD status, etiology of left ventricular dysfunction, wide (>/=120 ms) versus narrow (<120 ms) QRS duration, or fQRS myocardial territory. CONCLUSIONS: In this prospective, multisite cohort of primary prevention patients with left ventricular dysfunction, the presence of fQRS on ECG was not associated with a higher risk of either all-cause or arrhythmic mortality. These findings do not provide evidence that fQRS would be effective in risk stratifying primary prevention patients eligible for ICD therapy.

Impact of age and medical comorbidity on the effectiveness of implantable cardioverter-defibrillators for primary prevention.

BACKGROUND: Although implantable cardioverter-defibrillators (ICDs) reduce mortality in primary prevention patients with left ventricular systolic dysfunction, recent studies have questioned their overall role in clinical practice, especially in older patients and those with major comorbid conditions. METHODS AND RESULTS: In a prospective cohort of 965 patients with ischemic and nonischemic cardiomyopathies (ejection fraction or=75), ischemic etiology, ejection fraction (>25% versus 0.05). Incremental cost-effectiveness ratios for ICD therapy were similar between patients aged >or=75 years and younger patients but rose slightly in those with multiple comorbid conditions. CONCLUSIONS: Routine use of ICDs in primary prevention patients with left ventricular systolic dysfunction was associated with lower all-cause mortality, even among older patients and those with major comorbid conditions. Although their use needs to be individualized, our findings suggest that these groups should not be routinely excluded from ICD treatment.

Comparison of ultrafiltration, nesiritide, and usual care in acute decompensated heart failure.

To study the short-term effects of initial treatment strategies for acute decompensated heart failure, 25 patients treated with ultrafiltration (UF) were retrospectively compared with 25 patients treated with usual care (UC) and 25 patients treated with UC plus adjunctive nesiritide infusion (UN), matched for age, sex, ejection fraction, etiology, and serum creatinine. The median length of hospitalization was 6 days for UF, 4 days for UC, and 6 days for UN. All-cause 30-day readmissions tended to be fewer in the UF (16%) compared with the UN (24%) or UC (24%) groups. All groups lost weight, although to a greater extent in the UF group (15.8 lb vs 6.3 lb in UC and 4.7 lb in UN). Concomitantly, UF manifested the greatest increase in serum urea nitrogen, creatinine, and the number of patients with creatinine increases of >0.5 mg/dL (44% vs 24% in UC and 20% in UN). In acute decompensated heart failure, UF appears to be more effective for volume removal and possibly prevention of all-cause hospital readmission to 30 days than UC or UN. These findings, as well as the effects on renal function and length of stay, need to be further evaluated in a prospective randomized study.

Usefulness of microvolt T-wave alternans to predict outcomes in patients with ischemic cardiomyopathy beyond one year.

Previous studies have demonstrated that microvolt T-wave alternans (MTWA) screening effectively risk-stratifies patients with ischemic cardiomyopathy. Whether the prognostic utility of MTWA diminishes over 3 years of follow-up remains unknown. In this study, a prospective cohort of 768 patients with ischemic cardiomyopathy (left ventricular ejection fraction <35%) and no previous sustained ventricular arrhythmia was developed, of whom 514 (67%) screened MTWA nonnegative (positive and indeterminate). The mean follow-up period was 18 +/- 11 months. The primary end point was all-cause mortality and appropriate implantable cardioverter-defibrillator shocks. Stratified Cox regression analyses (by implantable cardioverter-defibrillator status) estimated the predictive power of MTWA within each year of follow-up and determined whether this diminished over time. There were 99 deaths (MTWA negative: 21 [8.3%]; MTWA nonnegative: 78 [15.2%]) and 33 appropriate implantable cardioverter-defibrillator shocks (MTWA negative: 3 [4.0%]; MTWA nonnegative: 30 [9.5%]). After multivariate adjustment, a nonnegative MTWA test result was associated with a greater than twofold increased risk for events in each of the 3 years of follow-up (year 1: stratified hazard ratio 2.19, 95% confidence interval 1.10 to 4.34, p = 0.03; year 2: stratified hazard ratio 3.36, 95% confidence interval 1.28 to 8.83, p = 0.01; year 3: stratified hazard ratio 2.06, 95% confidence interval 0.81 to 5.22, p = 0.13). There were no significant interactions between the time periods (year 1 vs year 2: p = 0.47; year 1 vs year 3: p = 0.92). In conclusion, MTWA reliably and consistently predicts mortality and arrhythmic risk throughout the first 2 to 3 years of follow-up. Although these findings need further validation, they suggest that rescreening with MTWA may not need to be performed more frequently than once every 2 years.

Relationship of a quality measure composite to clinical outcomes for patients with heart failure.

BACKGROUND: To determine whether compliance with heart failure performance measures (HFPMs) is associated with short-term outcome benefit. METHODS: In a cohort study, 194 patients satisfying all the HFPMs for which they were eligible were compared with 206 controls. Over 6 months, time to death and first all-cause readmission data were collected. Data were adjusted for differences in comorbidities, medications, and demographics in a multivariate model. RESULTS: There was no difference in 6-month mortality between the 2 groups. Adjusted time to death or all-cause hospitalization (hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.58-0.97; P = .03) and all-cause hospitalization (HR, 0.74; 95% CI, 0.57-0.97; P = .03) were shorter for the study group compared with control, whereas there was no difference in time to death (HR, 0.86; 95% CI, 0.66-1.11; P = .24). CONCLUSIONS: Adherence to a composite of HFPM appears to be related to a reduction in all-cause readmissions for patients with HF but not short-term mortality.

Usefulness of microvolt T-wave alternans on predicting outcome in patients with ischemic cardiomyopathy with and without defibrillators.

Microvolt T-wave alternans (MTWA) was proposed as an effective tool to identify high-risk patients with ischemic cardiomyopathy. However, previous studies suggested that the prognostic utility of MTWA may be limited to only patients with normal QRS duration. It therefore was assessed whether MTWA and QRS duration >120 ms independently predict mortality in patients with ischemic cardiomyopathy and whether the prognostic utility of MTWA differs by QRS duration. A total of 768 consecutive patients with ischemic cardiomyopathy (left ventricular ejection fraction < or =35%) and no history of ventricular arrhythmia were enrolled, of whom 514 (67%) screened MTWA non-negative (positive or indeterminate) and 223 (29%) had a QRS >120 ms on resting electrocardiogram. After multivariable adjustment, a non-negative MTWA test result was associated with a significantly higher risk for all-cause mortality in patients without an implantable cardioverter-defibrillator (ICD) (hazard ratio [HR] 2.27, 95% confidence interval [CI] 1.22 to 4.24, p = 0.01) and for all-cause mortality and appropriate ICD shocks in patients with an ICD (HR 2.42, 95% CI 1.07 to 5.41, p = 0.04). In contrast, a QRS >120 ms was not associated with all-cause mortality and ICD shocks in patients without (HR 0.96, 95% CI 0.52 to 1.75, p = 0.88) or with an ICD (HR 1.25, 95% CI 0.76 to 2.08, p = 0.40). No significant interaction was found between MTWA and QRS >120 ms (non-ICD p = 0.19, ICD p = 0.73). In conclusion, MTWA, but not QRS duration, predicted mortality outcomes in patients with ischemic cardiomyopathy. Moreover, the prognostic utility of MTWA did not appear to differ by QRS duration.