Extracorporeal life support in mitral papillary muscle rupture: Outcome of multicenter study.

BACKGROUND: Post-acute myocardial infarction papillary muscle rupture (post-AMI PMR) may present variable clinical scenarios and degree of emergency due to result of cardiogenic shock. Veno-arterial extracorporeal life support (V-A ECLS) has been proposed to improve extremely poor pre- or postoperative conditions. Information in this respect is scarce. METHODS: From the CAUTION (meChanical complicAtion of acUte myocardial infarcTion: an InternatiOnal multiceNter cohort study) database (16 different Centers, data from 2001 to 2018), we extracted adult patients who were surgically treated for post-AMI PMR and underwent pre- or/and postoperative V-A ECLS support. The end-points of this study were in-hospital survival and ECLS complications. RESULTS: From a total of 214 post-AMI PMR patients submitted to surgery, V-A ECLS was instituted in 23 (11%) patients. The median age was 61.7 years (range 46-81 years). Preoperatively, ECLS was commenced in 10 patients (43.5%), whereas intra/postoperative in the remaining 13. The most common V-A ECLS indication was post-cardiotomy shock, followed by preoperative cardiogenic shock and cardiac arrest. The median duration of V-A ECLS was 4 days. V-A ECLS complications occurred in more than half of the patients. Overall, in-hospital mortality was 39.2% (9/23), compared to 22% (42/219) for the non-ECLS group. CONCLUSIONS: In post-AMI PMR patients, V-A ECLS was used in almost 10% of the patients either to promote bridge to surgery or as postoperative support. Further investigations are required to better evaluate a potential for increased use and its effects of V-A ECLS in such a context based on the still high perioperative mortality.

Surgical treatment for post-infarction papillary muscle rupture: a multicentre study.

OBJECTIVES: Papillary muscle rupture (PMR) is a rare but potentially fatal complication of acute myocardial infarction. The aim of this study was to analyse the patient characteristics and early outcomes of the surgical management of post-infarction PMR from an international multicentre registry. METHODS: Patients underwent surgery for post-infarction PMR between 2001 through 2019 were retrieved from database of the CAUTION study. The primary end point was in-hospital mortality. RESULTS: A total of 214 patients were included with a mean age of 66.9 (standard deviation: 10.5) years. The posteromedial papillary muscle was the most frequent rupture location (71.9%); the rupture was complete in 67.3% of patients. Mitral valve replacement was performed in 82.7% of cases. One hundred twenty-two patients (57%) had concomitant coronary artery bypass grafting. In-hospital mortality was 24.8%. Temporal trends revealed no apparent improvement in in-hospital mortality during the study period. Multivariable analysis showed that preoperative chronic kidney disfunction [odds ratio (OR): 2.62, 95% confidence interval (CI): 1.07-6.45, P = 0.036], cardiac arrest (OR: 3.99, 95% CI: 1.02-15.61, P = 0.046) and cardiopulmonary bypass duration (OR: 1.01, 95% CI: 1.00-1.02, P = 0.04) were independently associated with an increased risk of in-hospital death, whereas concomitant coronary artery bypass grafting was identified as an independent predictor of early survival (OR: 0.38, 95% CI: 0.16-0.92, P = 0.031). CONCLUSIONS: Surgical treatment for post-infarction PMR carries a high in-hospital mortality rate, which did not improve during the study period. Because concomitant coronary artery bypass grafting confers a survival benefit, this additional procedure should be performed, whenever possible, in an attempt to improve the outcome. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov: NCT03848429.

Surgical Treatment of Postinfarction Ventricular Septal Rupture.

Importance: Ventricular septal rupture (VSR) is a rare but life-threatening mechanical complication of acute myocardial infarction associated with high mortality despite prompt treatment. Surgery represents the standard of care; however, only small single-center series or national registries are usually available in literature, whereas international multicenter investigations have been poorly carried out, therefore limiting the evidence on this topic. Objectives: To assess the clinical characteristics and early outcomes for patients who received surgery for postinfarction VSR and to identify factors independently associated with mortality. Design, Setting, and Participants: The Mechanical Complications of Acute Myocardial Infarction: an International Multicenter Cohort (CAUTION) Study is a retrospective multicenter international cohort study that includes patients who were treated surgically for mechanical complications of acute myocardial infarction. The study was conducted from January 2001 to December 2019 at 26 different centers worldwide among 475 consecutive patients who underwent surgery for postinfarction VSR. Exposures: Surgical treatment of postinfarction VSR, independent of the technique, alone or combined with other procedures (eg, coronary artery bypass grafting). Main Outcomes and Measures: The primary outcome was early mortality; secondary outcomes were postoperative complications. Results: Of the 475 patients included in the study, 290 (61.1%) were men, with a mean (SD) age of 68.5 (10.1) years. Cardiogenic shock was present in 213 patients (44.8%). Emergent or salvage surgery was performed in 212 cases (44.6%). The early mortality rate was 40.4% (192 patients), and it did not improve during the nearly 20 years considered for the study (median [IQR] yearly mortality, 41.7% [32.6%-50.0%]). Low cardiac output syndrome and multiorgan failure were the most common causes of death (low cardiac output syndrome, 70 [36.5%]; multiorgan failure, 53 [27.6%]). Recurrent VSR occurred in 59 participants (12.4%) but was not associated with mortality. Cardiogenic shock (survived: 95 [33.6%]; died, 118 [61.5%]; P < .001) and early surgery (time to surgery ≥7 days, survived: 105 [57.4%]; died, 47 [35.1%]; P < .001) were associated with lower survival. At multivariate analysis, older age (odds ratio [OR], 1.05; 95% CI, 1.02-1.08; P = .001), preoperative cardiac arrest (OR, 2.71; 95% CI, 1.18-6.27; P = .02) and percutaneous revascularization (OR, 1.63; 95% CI, 1.003-2.65; P = .048), and postoperative need for intra-aortic balloon pump (OR, 2.98; 95% CI, 1.46-6.09; P = .003) and extracorporeal membrane oxygenation (OR, 3.19; 95% CI, 1.30-7.38; P = .01) were independently associated with mortality. Conclusions and Relevance: In this study, surgical repair of postinfarction VSR was associated with a high risk of early mortality; this risk has remained unchanged during the last 2 decades. Delayed surgery seemed associated with better survival. Age, preoperative cardiac arrest and percutaneous revascularization, and postoperative need for intra-aortic balloon pump and extracorporeal membrane oxygenation were independently associated with early mortality. Further prospective studies addressing preoperative and perioperative patient management are warranted to hopefully improve the currently suboptimal outcome.

Exercise Hemodynamic and Functional Capacity After Mitral Valve Replacement in Patients With Ischemic Mitral Regurgitation: A Comparison of Mechanical Versus Biological Prostheses.

BACKGROUND: In patients with ischemic mitral regurgitation requiring mitral valve replacement (MVR), the choice of the prosthesis type is crucial. The exercise hemodynamic and functional capacity performance in patients with contemporary prostheses have never been investigated. To compare exercise hemodynamic and functional capacity between biological (MVRb) and mechanical (MVRm) prostheses. METHODS AND RESULTS: We analyzed 86 consecutive patients with ischemic mitral regurgitation who underwent MVRb (n=41) or MVRm (n=45) and coronary artery bypass grafting. All patients underwent preoperative resting echocardiography and 6-minute walking test. At follow-up, exercise stress echocardiography was performed, and the 6-minute walking test was repeated. Resting and exercise indexed effective orifice areas of MVRm were larger when compared with MVRb (resting: 1.30±0.2 versus 1.19±0.3 cm2/m2; P=0.03; exercise: 1.57±0.2 versus 1.18±0.3 cm2/m2; P=0.0001). The MVRm had lower exercise systolic pulmonary arterial pressure at follow-up compared with MVRb (41±5 versus 59±7 mm Hg; P=0.0001). Six-minute walking test distance was improved in the MVRm (pre-operative: 242±43, post-operative: 290±50 m; P=0.001), whereas it remained similar in the MVRb (pre-operative: 250±40, post-operative: 220±44 m; P=0.13). In multivariable analysis, type of prosthesis, exercise indexed effective orifice area, and systolic pulmonary arterial pressure were joint predictors of change in 6-minute walking test (ie, difference between baseline and follow-up). CONCLUSIONS: In patients with ischemic mitral regurgitation, bioprostheses are associated with worse hemodynamic performance and reduced functional capacity, when compared with MVRm. Randomized studies with longer follow-up including quality of life and survival data are required to confirm these results.

Echocardiographic outflow pump ramp test in centrifugal-flow left ventricular assist device.

This study sought to develop a novel echocardiogram outflow ramp test to detect device malfunctions in centrifugal-flow left ventricular assist devices (LVADs). This new ramp pump test is based on the direct analyses of systolic and diastolic ratio (S/D) Doppler velocity in the outflow cannula in the HeartWare LVAD during progressive increases in speed. The results showed that in patients with normal pump function, the Doppler velocity S/D ratio gradually decreased during LVAD speed increases. This test is easily performed and seems promising to detect normal pump function in patients assisted by a centrifugal flow LVAD.

Determinants of functional capacity after mitral valve annuloplasty or replacement for ischemic mitral regurgitation.

OBJECTIVE: To identify the exercise echocardiographic determinants of long-term functional capacity, in patients with chronic ischemic mitral regurgitation, after restrictive mitral valve annuloplasty (RMA) or mitral valve replacement (MVR). METHODS: We retrospectively analyzed 121 patients with significant chronic ischemic mitral regurgitation, who underwent RMA (n = 62) or MVR (n = 59), between 2005 and 2011. Preoperatively, all patients underwent a resting echocardiographic examination, and a 6-minute walking test (6-MWT) to measure distance. Resting and exercise stress echocardiography, and the 6-MWT were repeated at 41 ± 16.5 months. RESULTS: After surgery, the 6-MWT distance significantly improved in the MVR group, and decreased in the RMA group (+37 ± 39 m vs -24 ± 49 m, respectively; P < .0001). Exercise indexed effective orifice area was significantly higher in the MVR, versus the RMA, group (MVR: change from 1.3 ± 0.2 cm(2)/m(2) to 1.5 ± 0.3 cm(2)/m(2); RMA: change from 1.1 ± 0.3 cm(2)/m(2) to 1.2 ± 0.3 cm(2)/m(2); P = .001). The mean mitral gradients significantly increased from rest to exercise, in both groups, but to a greater extent in the RMA group (change from 4.4 ± 1.4 to 11 ± 3.6 mm Hg; MVR: change from 4.3 ± 1.8 to 9 ± 3.5 mm Hg; P = .006). On multivariate analysis, MVR and exercise indexed effective orifice area were the main independent determinants of postoperative 6-MWT. In the RMA group, 25 patients experienced late mitral regurgitation recurrence, severe in 9 (14%) of them. The rate of postoperative cardiovascular events was significantly higher in the RMA group (21% vs MVR: 8%; P = .03). Follow-up survival was 83% in the RMA group and 88% in the MVR group (P = .54). CONCLUSIONS: For chronic ischemic mitral regurgitation, MVR versus RMA was associated with better postoperative exercise hemodynamic performance and long-term functional capacity.

Restrictive mitral valve annuloplasty versus mitral valve replacement for functional ischemic mitral regurgitation: an exercise echocardiographic study.

OBJECTIVE: Mitral valve annuloplasty and mitral valve replacement are common strategies for the management of functional ischemic mitral regurgitation with ischemic cardiomyopathy. However, mitral valve annuloplasty may create some degree of functional mitral stenosis. The purpose of this study was to compare the mitral valve hemodynamics in patients with functional ischemic mitral regurgitation undergoing mitral valve annuloplasty or mitral valve replacement, using exercise echocardiography. METHODS: We performed resting and exercise echocardiography in 70 patients matched for indexed effective orifice area, systolic pulmonary arterial pressure, and left ventricular ejection fraction after mitral valve annuloplasty or mitral valve replacement with coronary artery bypass grafting. RESULTS: There was no significant difference between the 2 groups regarding baseline demographic and clinical data. Exercise systolic pulmonary arterial pressure was higher in the mitral valve annuloplasty group compared with the mitral valve replacement group (from 36.3 ± 8.1 mm Hg to 55 ± 12 mm Hg, vs mitral valve replacement: 33 ± 6 mm Hg to 42 ± 6.2 mm Hg, P = .0001). Exercise-induced improvement in effective orifice area and indexed effective orifice area was better in the mitral valve replacement group (mitral valve replacement: +0.23 ± 0.04 vs mitral valve annuloplasty: -0.1 ± 0.09 cm², P = .001, for effective orifice area; mitral valve replacement: +0.14 ± 0.03 vs mitral valve annuloplasty: -0.04 ± 0.07 cm²/m², P = .03, for indexed effective orifice area). Exercise indexed effective orifice area was correlated with exercise systolic pulmonary arterial pressure (r = -0.45; P = .01). In a multivariable analysis mitral valve annuloplasty, postoperative indexed effective orifice area and resting mitral peak gradients were independent predictors of elevated systolic pulmonary arterial pressure during exercise. CONCLUSIONS: In patients with functional ischemic mitral regurgitation, mitral valve annuloplasty may cause functional mitral stenosis, especially during exercise. Mitral valve annuloplasty was associated with poor exercise mitral hemodynamic performance, lack of mitral valve opening reserve, and markedly elevated postoperative exercise systolic pulmonary arterial pressure compared with mitral valve replacement.

Mitral valve repair or replacement for ischemic mitral regurgitation? The Italian Study on the Treatment of Ischemic Mitral Regurgitation (ISTIMIR).

OBJECTIVE: It is uncertain whether mitral valve replacement is really inferior to mitral valve repair for the treatment of chronic ischemic mitral regurgitation. This multicenter study aimed at providing a contribution to this issue. METHODS: Of 1006 patients with chronic ischemic mitral regurgitation and impaired left ventricular function (ejection fraction < 40%) operated on at 13 Italian institutions between 1996 and 2011, 298 (29.6%) underwent mitral valve replacement whereas 708 (70.4%) received mitral valve repair. Propensity scores were calculated by a nonparsimonious multivariable logistic regression, and 244 pairs of patients were matched successfully using calipers of width 0.2 standard deviation of the logit of the propensity scores. The postmatching median standardized difference was 0.024 (range, 0-0.037) and in none of the covariates did it exceed 10%. RESULTS: Early deaths were 3.3% (n = 8) in mitral valve repair versus 5.3% (n = 13) in mitral valve replacement (P = .32). Eight-year survival was 81.6% ± 2.8% and 79.6% ± 4.8% (P = .42), respectively. Actual freedom from all-cause reoperation and valve-related reoperation were 64.3% ± 4.3% versus 80% ± 4.1%, and 71.3% ± 3.5% versus 85.5% ± 3.9 in mitral valve repair and mitral valve replacement, respectively (P < .001). Actual freedom from all valve-related complications was 68.3% ± 3.1% versus 69.9% ± 3.3% in mitral valve repair and mitral valve replacement, respectively (P = .78). Left ventricular function did not improved significantly, and it was comparable in the 2 groups postoperatively (36.9% vs 38.5%, P = .66). At competing regression analysis, mitral valve repair was a strong predictor of reoperation (hazard ratio, 2.84; P < .001). CONCLUSIONS: Mitral valve replacement is a suitable option for patients with chronic ischemic mitral regurgitation and impaired left ventricular function. It provides better results in terms of freedom from reoperation with comparable valve-related complication rates.

Warm-blood cardioplegia with low or high magnesium for coronary bypass surgery: a randomised controlled trial.

OBJECTIVE: Magnesium (Mg²âº) is cardioprotective and has been routinely used to supplement cardioplegic solutions during coronary artery bypass graft (CABG) surgery. However, there is no consensus about the Mg²âº concentration that should be used. The aim of this study was to compare the effects of intermittent antegrade warm-blood cardioplegia supplemented with either low- or high-concentration Mg²âº. METHODS: This study was a randomised controlled trial carried out in two cardiac surgery centres, Bristol, UK and Cuneo, Italy. Patients undergoing isolated CABG with cardiopulmonary bypass were eligible. Patients were randomised to receive warm-blood cardioplegia supplemented with 5 or 16 mmol l⁻¹ Mg². The primary outcome was postoperative atrial fibrillation. Secondary outcomes were serum biochemical markers (troponin I, Mg²âº, potassium, lactate and creatinine) and time-to-plegia arrest. Intra-operative and postoperative clinical outcomes were also recorded. RESULTS: Data from two centres for 691 patients (342 low and 349 high Mg²âº) were analysed. Baseline characteristics were similar for both groups. There was no significant difference in the frequency of postoperative atrial fibrillation in the high (32.8%) and low (32.0%) groups (risk ratio 1.03, 95% confidence interval, CI, 0.82-1.28). However, compared with the low group, troponin I release was 28% less (95% CI 55-94%, p=0.02) in the high-Mg²âº group. The 30-day mortality was 0.72% (n = 5); all deaths occurred in the high-Mg²âº group but there was no significant difference between the groups (p=0.06). Frequencies of other major complications were similar in the two groups. CONCLUSIONS: Warm-blood cardioplegia supplemented with 16 mmol l⁻¹ Mg²âº, compared with 5 mmol l⁻¹ Mg²âº, does not reduce the frequency of postoperative atrial fibrillation in patients undergoing CABG but may reduce cardiac injury. (This trial was registered as ISRCTN95530505.).

High OPCAB surgical volume improves midterm event-free survival.

BACKGROUND: The aim of this study was to evaluate the midterm results of the initial phase of off-pump coronary artery bypass (OPCAB) surgery adoption in a single surgical unit, assessing the impact of procedural volume. METHODS: Study participants were 312 patients who underwent OPCAB during the period between August 2000 and January 2005 at S. Croce Hospital. Of these patients, 126 patients with an indication selected for comorbidities or 1-vessel disease underwent OPCAB performed by 4 low-volume surgeons, and 186 unselected patients underwent OPCAB performed by a single high-volume surgeon. RESULTS: OPCAB performed by low-volume surgeons was associated with less complete revascularization and less arterial conduit use. Early result analysis showed a low rate of in-hospital or 30-day adverse events. The 5-year survival was 0.88 (0.02 SE). OPCAB performance by a high-volume surgeon and complete revascularization were shown have a protective effect for midterm major adverse cardiac events (respectively, hazard ratio = 0.28, 95% confidence interval 0.11-0.74 and hazard ratio = 0.33, 95% confidence interval 0.15-0.73). CONCLUSION: Our study on the initial phase of OPCAB adoption suggests a benefit on midterm outcome from surgery performed by a high-volume surgeon.

Impact of incomplete revascularization following OPCAB surgery.

BACKGROUND AND AIM OF THE STUDY: The aim of this study was to evaluate the early and mid-term off-pump coronary artery bypass surgery (OPCAB) results in a single surgical unit, assessing the impact of completeness of revascularization. METHODS: Three hundred and twelve patients underwent OPCAB between August 2000 and January 2005. In-hospital data were collected prospectively for all patients undergoing OPCAB. Complete revascularization (CR) was derived by comparing significantly stenotic vessels at cardiac catheterization with surgically grafted coronary vessels. Grafting of all the significantly stenotic coronary vessels was considered CR. In-hospital outcomes were compared between patients with CR and incomplete revascularization (IR). A multivariate analysis based on the Cox proportional hazards regression model was performed. RESULTS: Patients receiving IR (105 patients, 43.7%) presented a worse preoperative risk profile then those having CR (mean Euroscore 6.8 +/- 2.9 vs. 4.3 +/- 2.8, p < 0.0001). IR was not associated with a higher incidence of early adverse events. Five-year freedom from death and major adverse cardiac events (MACE) were 0.88 (0.02 SE) and 0.86 (0.03 SE), respectively. Complete revascularization was protective for mid-term unstable angina recurrence [heart rate (HR) = 0.24, 95% confidence interval (CI) 0.10 to 0.58], acute myocardial infarction (HR = 0.25, 95% CI 0.09 to 0.73), all-cause repeat revascularization (HR = 0.35, 95% CI 0.13 to 0.90), and MACE (HR = 0.2, 95% CI 0.1 to 0.5). CONCLUSION: Our study suggests that, although incomplete revascularization may not result in increased short-term morbidity and mortality, it increases the incidence of mid-term MACE.

Effects of angiotensin-converting enzyme inhibitor therapy on clinical outcome in patients undergoing coronary artery bypass grafting.

OBJECTIVES: This study evaluates the effect of pre-operative angiotensin-converting enzyme inhibitor (ACEI) therapy on early clinical outcomes after coronary artery bypass grafting (CABG). BACKGROUND: Therapy with ACEIs has been shown to reduce the rate of mortality and prevent cardiovascular events in patients with coronary artery disease. However, their pre-operative use in patients undergoing CABG is still controversial. METHODS: A retrospective, observational, cohort study was undertaken of prospectively collected data on 10,023 consecutive patients undergoing isolated CABG between April 1996 and May 2008. Of these, 3,052 patients receiving pre-operative ACEI were matched to a control group by propensity score analysis. RESULTS: Overall rate of mortality was 1%. Pre-operative ACEI therapy was associated with a doubling in the risk of death (1.3% vs. 0.7%; odds ratio [OR]: 2.00, 95% confidence interval [CI]: 1.17 to 3.42; p = 0.013). There was also a significant difference between the ACEI and control group in the risk of post-operative renal dysfunction (PRD) (7.1% vs. 5.4%; OR: 1.36, 95% CI: 1.1 to 1.67; p = 0.006), atrial fibrillation (AF) (25% vs. 20%; OR: 1.34, 95% CI: 1.18 to 1.51; p < 0.0001), and increased use of inotropic support (45.9% vs. 41.1%; OR: 1.22, 95% CI: 1.1 to 1.36; p < 0.0001). In a multivariate analysis, pre-operative ACEI treatment was an independent predictor of mortality (p = 0.04), PRD (p = 0.0002), use of inotropic drugs (p < 0.0001), and AF (p < 0.0001). CONCLUSIONS: Pre-operative therapy with ACEI is associated with an increased risk of mortality, use of inotropic support, PRD, and new onset of post-operative AF.

Effects of preoperative statin treatment on the incidence of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting.

BACKGROUND: Postoperative atrial fibrillation is still a common complication in patients undergoing coronary artery bypass grafting. The aim of this study was to evaluate the effect of preoperative statin therapy on new onset of postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting. METHODS: Of 8,946 patients undergoing isolated coronary artery bypass grafting at the Bristol Heart Institute from April 1996 to September 2006, 6,321 (70.6%) received preoperative statins. Of these, 2,152 patients (statin group) were matched to a control group (no statin) by propensity score analysis. RESULTS: Preoperative characteristics, number of distal anastomoses, and the use of off -pump procedures were similar in both groups. Hospital mortality was 1.3% (56 patients) with no difference between the two groups. Postoperative atrial fibrillation was significantly higher in the statin compared with the no statin group (411, 19.5%, versus 336; 15.8% respectively; p = 0.002). In a multivariate regression analysis, age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02 to 1.05), pulmonary disease (OR, 1.42; 95% CI, 1.12-1.82), history of paroxysmal atrial fibrillation (OR, 3; 95% CI, 2.13 to 4.19), preoperative angiotensin-converting enzyme inhibitor therapy (OR, 1.26; 95% CI, 1.07 to 1.49), ejection fraction less than 0.30 (OR, 1.71; 95% CI, 1.22 to 2.38), emergency operations (OR, 4.5; 95% CI, 2 to 10.12), and preoperative statin treatment (OR, 1.31; 95% CI, 1.11 to 1.55) were all independent predictors of postoperative atrial fibrillation. CONCLUSIONS: Preoperative statin is associated with a significantly higher incidence of postoperative atrial fibrillation compared with no statin treatment in patients undergoing isolated coronary artery bypass grafting.