Thomas Modine

Does off-pump coronary artery bypass (OPCAB) surgery improve the outcome in high-risk patients?: a comparative study of 1398 high-risk patients

OBJECTIVE Although there has been some evidence supporting the theoretical and practical advantages of off-pump coronary artery bypass (OPCAB) over the conventional coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB), it has not yet been determined which group of patients would benefit most from it. It has been advocated recently that high-risk patients could benefit most from avoidance of CPB. The aim of this retrospective study is to assess the efficacy of the OPCAB technique in multi-vessel myocardial revascularization in a large series of high-risk patients. METHODS The records of 1398 consecutive high-risk patients who underwent primary isolated CABG at Harefield Hospital between August 1996 and December 2001 were reviewed retrospectively. Patients were considered as high-risk and included in the study if they had a preoperative EuroSCORE of > or =5. Two hundred and eighty-six patients were operated on using the OPCAB technique while 1112 patients were operated on using the conventional CABG technique with CPB. The OPCAB patients were significantly older than the CPB patients (68.1+/-8.3 vs. 63.7+/-9.9 years, respectively, P<0.001). The OPCAB group included significantly more patients with poor left ventricular (LV) function (ejection fraction (EF) < or =30%) (P<0.001) and more patients with renal problems (P<0.001). RESULTS There was no significant difference in the number of grafts between the groups. The CPB patients received 2.8+/-1.2 grafts per patient while OPCAB patients received 2.8+/-0.5 grafts per patient (P=1). Twenty-one (7.3%) OPCAB patients had one or more major complications, while 158 (14.2%) CPB patients (P=0.008) developed major complications. Thirty-eight (3.4%) CPB patients developed peri-operative myocardial infarction (MI) while only two (0.7%) OPCAB patients developed peri-operative MI (P=0.024). The intensive therapy unit (ITU) stay for OPCAB patients was 29.3+/-15.4 h while for CPB patients it was 63.6+/-167.1 h (P<0.001). There were ten (3.5%) deaths in the OPCAB patients compared to 78 (7%) deaths in the CPB patients (P=0.041) within 30 days postoperatively. CONCLUSIONS This retrospective study shows that using the OPCAB technique for multi-vessel myocardial revascularization in high-risk patients significantly reduces the incidence of peri-operative MI and other major complications, ITU stay and mortality. Even though the OPCAB group included a significantly higher proportion of older patients with poor LV function (EF < or =30%) and renal problems, the beneficial effect of OPCAB was evident.

Transcatheter Aortic Valve Implantation for Pure Severe Native Aortic Valve Regurgitation

OBJECTIVES This study sought to collect data and evaluate the anecdotal use of transcatheter aortic valve implantation (TAVI) in pure native aortic valve regurgitation (NAVR) for patients who were deemed surgically inoperable BACKGROUND Data and experience with TAVI in the treatment of patients with pure severe NAVR are limited. METHODS Data on baseline patient characteristics, device and procedure parameters, echocardiographic parameters, and outcomes up to July 2012 were collected retrospectively from 14 centers that have performed TAVI for NAVR. RESULTS A total of 43 patients underwent TAVI with the CoreValve prosthesis (Medtronic, Minneapolis, Minnesota) at 14 centers (mean age, 75.3 ± 8.8 years; 53% female; mean logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation), 26.9 ± 17.9%; and mean Society of Thoracic Surgeons score, 10.2 ± 5.3%). All patients had severe NAVR on echocardiography without aortic stenosis and 17 patients (39.5%) had the degree of aortic valvular calcification documented on CT or echocardiography. Vascular access was transfemoral (n = 35), subclavian (n = 4), direct aortic (n = 3), and carotid (n = 1). Implantation of a TAVI was performed in 42 patients (97.7%), and 8 patients (18.6%) required a second valve during the index procedure for residual aortic regurgitation. In all patients requiring second valves, valvular calcification was absent (p = 0.014). Post-procedure aortic regurgitation grade I or lower was present in 34 patients (79.1%). At 30 days, the major stroke incidence was 4.7%, and the all-cause mortality rate was 9.3%. At 12 months, the all-cause mortality rate was 21.4% (6 of 28 patients). CONCLUSIONS This registry analysis demonstrates the feasibility and potential procedure difficulties when using TAVI for severe NAVR. Acceptable results may be achieved in carefully selected patients who are deemed too high risk for conventional surgery, but the possibility of requiring 2 valves and leaving residual aortic regurgitation remain important considerations.

Transcatheter aortic valve replacement in bicuspid aortic valve disease.

BACKGROUND Limited information exists describing the results of transcatheter aortic valve (TAV) replacement in patients with bicuspid aortic valve (BAV) disease (TAV-in-BAV). OBJECTIVES This study sought to evaluate clinical outcomes of a large cohort of patients undergoing TAV-in-BAV. METHODS We retrospectively collected baseline characteristics, procedural data, and clinical follow-up findings from 12 centers in Europe and Canada that had performed TAV-in-BAV. RESULTS A total of 139 patients underwent TAV-in-BAV with the balloon-expandable transcatheter heart valve (THV) (n = 48) or self-expandable THV (n = 91) systems. Patient mean age and Society of Thoracic Surgeons predicted risk of mortality scores were 78.0 ± 8.9 years and 4.9 ± 3.4%, respectively. BAV stenosis occurred in 65.5%, regurgitation in 0.7%, and mixed disease in 33.8% of patients. Incidence of type 0 BAV was 26.7%; type 1 BAV was 68.3%; and type 2 BAV was 5.0%. Multislice computed tomography (MSCT)-based TAV sizing was used in 63.5% of patients (77.1% balloon-expandable THV vs. 56.0% self-expandable THV, p = 0.02). Procedural mortality was 3.6%, with TAV embolization in 2.2% and conversion to surgery in 2.2%. The mean aortic gradient decreased from 48.7 ± 16.5 mm Hg to 11.4 ± 9.9 mm Hg (p < 0.0001). Post-implantation aortic regurgitation (AR) grade ≥ 2 occurred in 28.4% (19.6% balloon-expandable THV vs. 32.2% self-expandable THV, p = 0.11) but was prevalent in only 17.4% when MSCT-based TAV sizing was performed (16.7% balloon-expandable THV vs. 17.6% self-expandable THV, p = 0.99). MSCT sizing was associated with reduced AR on multivariate analysis (odds ratio [OR]: 0.19, 95% confidence intervals [CI]: 0.08 to 0.45; p < 0.0001). Thirty-day device safety, success, and efficacy were noted in 79.1%, 89.9%, and 84.9% of patients, respectively. One-year mortality was 17.5%. Major vascular complications were associated with increased 1-year mortality (OR: 5.66, 95% CI: 1.21 to 26.43; p = 0.03). CONCLUSIONS TAV-in-BAV is feasible with encouraging short- and intermediate-term clinical outcomes. Importantly, a high incidence of post-implantation AR is observed, which appears to be mitigated by MSCT-based TAV sizing. Given the suboptimal echocardiographic results, further study is required to evaluate long-term efficacy.

Myocardial Contractile Dysfunction Is Associated With Impaired Mitochondrial Function and Dynamics in Type 2 Diabetic but Not in Obese Patients

Background— Obesity and diabetes mellitus are independently associated with the development of heart failure. In this study, we determined the respective effects of obesity, insulin resistance, and diabetes mellitus on the intrinsic contraction and mitochondrial function of the human myocardium before the onset of cardiomyopathy. Methods and Results— Right atrial myocardium was obtained from 141 consecutive patients presenting no sign of cardiomyopathy. We investigated ex vivo isometric contraction, mitochondrial respiration and calcium retention capacity, and respiratory chain complex activities and oxidative stress status. Diabetes mellitus was associated with a pronounced impairment of intrinsic contraction, mitochondrial dysfunction, and increased myocardial oxidative stress, regardless of weight status. In contrast, obesity was associated with less pronounced contractile dysfunction without any significant perturbation of mitochondrial function or oxidative stress status. Tested as continuous variables, glycated hemoglobin A1C, but neither body mass index nor the insulin resistance index (homeostasis model assessment–insulin resistance), was independently associated with cardiac mitochondrial function. Furthermore, diabetes mellitus was associated with cardiac mitochondrial network fragmentation and significantly decreased expression of the mitochondrial fusion related protein MFN1. Myocardial MFN1 content was inversely proportional to hemoglobin A1C. Conclusion— Worsening of intrinsic myocardial contraction in the transition from obesity to diabetes mellitus is likely related to worsening of cardiac mitochondrial function because impaired mitochondrial function and dynamics and contractile dysfunction are observed in diabetic patients but not in “metabolically healthy” obese patients at early stage in insulin resistance.

Predictors of poor mid-term health related quality of life after primary isolated coronary artery bypass grafting surgery

Objective: To assess the determinants of poor mid-term health related quality of life (HRQoL) at one year after primary isolated coronary artery bypass grafting (CABG). Methods: 463 patients who underwent primary isolated CABG for multivessel disease and came for their annual follow up at the outpatient clinic during one year at Harefield Hospital, Middlesex, were approached to participate in the present study. Prospective clinical data were collected as part of the clinical care of the patients and were retrospectively analysed when the patients consented to participate in the study at their outpatient visit. After their consent they were given three HRQoL assessment questionnaires. Scores, together with clinical data, were analysed by both univariate and multivariate analyses with regard to poor HRQoL outcome. Results: 437 (94.4%) patients consented to participate in the study and filled in the HRQoL questionnaires. Ten variables were identified in the univariate analysis as potential predictors of poor scores of the physical element of HRQoL; however, only three variables—gastrointestinal problems, congestive heart failure, and type D personality trait—predicted poor physical scores independently. Eleven variables were identified in the univariate analysis as potential predictors of poor scores of the mental element of HRQoL; however, only three variables—peripheral vascular disease, infective complications, and type D personality trait—predicted poor physical scores independently. Conclusion: Preoperative gastrointestinal problems, preoperative congestive heart failure, and type D personality trait were independent predictors of the poor physical component of HRQoL. Peripheral vascular disease, infective complications, and type D personality trait were independent predictors of the poor mental component of HRQoL. Interestingly, patients with type D personality were more than twice as likely to have poor physical HRQoL and more than five times as likely to have poor mental HRQoL.

Echocardiography predictors and prognostic value of pulmonary artery systolic pressure in chronic organic mitral regurgitation

Objective To evaluate the predictors of pulmonary artery systolic pressure (PASP) in organic mitral regurgitation (MR) and its prognostic value after surgery. Design Prospective observational study, conducted from 1998 to 2006. Setting Echocardiography and cardiac surgery departments, University Hospital. Patients Echocardiography was carried out in 256 patients (63±12 years, 170 male) with organic MR (degenerative aetiology: 91%) referred for surgery. Main outcome measures Echocardiography predictors of PASP. Postoperative end points were overall mortality and cardiovascular mortality. Results Baseline PASP was 45±14 mmHg, ranging from 25 to 105 mmHg. PASP was ≥50 mmHg in 82 patients (32%). Left atrial volume (p=0.003), mitral deceleration time (p<0.0001) and mitral medial E/E′ (p<0.0001) were independent predictors of PASP, whereas left ventricular size and systolic function were not predictors. Mitral valve repair was performed in 194 patients (76%) and mitral valve replacement in 62 (24%). In a Cox model mitral valve repair (HR=0.41 (95% CI 0.20 to 0.85), p=0.016) and PASP (HR=1.43 (95% CI 1.09 to 1.88) per 10 mmHg increment, p=0.011) were independent predictors of overall mortality, even after adjustment for known predictors. PASP (HR=1.49 (95% CI 1.03 to 2.16) per 10 mmHg increment, p=0.033) was also an independent predictor of cardiac mortality. Eight-year survival after surgery was 58.6% and 86.6% in patients with baseline PASP ≥50 mmHg or <50 mmHg, respectively (p<0.0001). Conclusions In organic MR, mitral deceleration time, mitral E/E′ and left atrial volume correlate with PASP. Pulmonary artery systolic pressure ≥50 mmHg is an independent predictor of overall and cardiovascular mortality after surgery in organic MR.

Transcutaneous aortic valve implantation using the axillary/subclavian access: Feasibility and early clinical outcomes

OBJECTIVE Retrograde transfemoral artery catheterization is the most common way of implanting a percutaneous aortic valve. But in some cases, this access cannot be used and the subclavian artery access may represent an alternative to the femoral route, even offering certain advantages. This article describes prosthetic aortic valve implantation using the subclavian arterial approach and reports the findings. METHODS The valve prosthesis is a self-expandable, nitinol-based device (CoreValve; Medtronic Inc. Minneapolis, Minn). The axillary or subclavian artery was exposed with a small incision. Rapid ventricular pacing was used to reduce cardiac output while a routine aortic balloon valvuloplasty was performed. Then, an 18F sheath was inserted into the axillary artery down into the ascending aorta. By using this method, a prosthesis was implanted in 17 patients (aged 71±11 years) whose surgical risk was deemed excessive because of severe comorbidity and in whom transfemoral catheterization was considered unfeasible or at risk of severe complications. RESULTS Subclavian arterial injury did not occur in any patient. The postprocedural aortic valve area increased from 0.6±0.3 cm2 to 1.44±0.35 cm2. A transient ischemic attack occurred in 1 patient. Two patients experienced transitory brachial plexus deficit. There were no intraprocedural deaths. Two deaths occurred in the 30-day follow-up period. CONCLUSIONS This initial experience suggests that subclavian transarterial aortic valve implantation, in selected high-risk patients, is feasible and safe with satisfactory short-term outcomes.

Transcutaneous Aortic Valve Implantation Using the Left Carotid Access: Feasibility and Early Clinical Outcomes

BACKGROUND In some patients, transfemoral, transaxillary, or transapical aortic valve implantation is not possible. Thus, carotid artery access may represent a safe alternative to those accesses, and even offers certain advantages. In this article, we describe aortic valve implantation using the left carotid arterial approach and report our initial experience. METHODS Using a self-expandable nitinol based device (CoreValve ReValving system, Medtronic Ltd, Luxembourg), we exposed the left carotid artery through a small incision. Arterial puncture and initial 6F sheath introduction were achieved through a contraincision. The same implantation technique as for transaxillary implantation was used. Progressive artery dilatation was achieved using sheaths of increasing diameter. Rapid ventricular pacing was used to reduce cardiac output while performing a routine aortic balloon valvuloplasty. Only then, an 18F sheath was inserted into the carotid artery and pushed down into the ascending aorta. The patients were monitored using cerebral oxymetry to assess cerebral perfusion. RESULTS Twelve consecutive patients, at high surgical risk, were implanted and studied prospectively. Transfemoral and subclavian catheterization were considered unfeasible or at risk of severe complications. Carotid arterial injury did not occur in any patient. A transient ischemic attack occurred in 1 patient, contralateral to the carotid access. There were no deaths in either intraprocedural or during the 30-day follow-up period. CONCLUSIONS This initial experience suggests that left carotid transarterial aortic valve implantation, in selected high-risk patients, is feasible and safe with satisfactory short-term outcomes.

Mitochondrial dysfunction as an arrhythmogenic substrate: a translational proof-of-concept study in patients with metabolic syndrome in whom post-operative atrial fibrillation develops.

OBJECTIVES This study sought to provide bedside evidence of the potential link between cardiac mitochondrial dysfunction and arrhythmia as reported in bench studies. BACKGROUND Atrial fibrillation (AF) is a frequent complication of cardiac surgery. Underlying mechanisms of post-operative atrial fibrillation (POAF) remain largely unknown. Because cardiac mitochondrial dysfunction has been reported in clinical conditions with a high risk of POAF, we investigated whether a causal link exists between POAF onset and pre-operative function of cardiac mitochondria. METHODS Pre-operative mitochondrial respiration and calcium retention capacity, respiratory complex activity, and myocardial oxidative stress were quantified in right atrial tissue from 104 consecutive patients with metabolic syndrome, in sinus rhythm, and undergoing coronary artery bypass graft surgery. RESULTS In this high-risk population, POAF occurred in 44% of patients. Decreased pre-operative mitochondrial respiration and increased sensitivity to calcium-induced mitochondrial permeability transition pore opening were significantly associated with POAF. Adenosine diphosphate-stimulated mitochondrial respiration supported by palmitoyl-l-carnitine was significantly lower in POAF patients and remained independently associated with AF onset after adjustment for age, body mass index, heart rate, beta-blocker use, and statin medication (multivariate logistic regression coefficient per unit = -0.314 ± 0.144; p = 0.028). Gene expression profile analysis identified a general downregulation of the mitochondria/oxidative phosphorylation gene cluster in pre-operative atrial tissue of patients in whom AF developed. CONCLUSIONS Our prospective study identifies an association between pre-operative mitochondrial dysfunction of the atrial myocardium and AF occurrence after cardiac surgery in patients with metabolic disease, providing novel insights into the link between mitochondria and arrhythmias in patients.

Update on the need for a permanent pacemaker after transcatheter aortic valve implantation using the CoreValve® Accutrak™ system.

AIMS High rates of permanent pacemaker (PPM) implantation are reported after transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve® system. The Accutrak™ catheter is designed to allow a more predictable landing zone. Little is known about the real clinical impact of this catheter. The aims of this paper were to describe the potential impact of the Accutrak™ catheter on the accuracy of positioning a 26 or 29 mm CoreValve® across the aortic annulus and its impact on the need for a pacemaker. METHODS AND RESULTS A total of 134 patients were treated with the CoreValve® Accutrak™ system at two French centres (Lille and Toulouse). Mean age was 82.4 ± 4.7 years; logistic EuroSCORE was 24.3 ± 9.5%. Procedural success rate was 99.2%; mean depth of implantation was 4.9 mm. A final position between 0 and 6 mm was achieved in 85.8% of the patients. All-cause mortality at 30 days was 6%. The PPM implantation rate was 10.6%. Due to a limited number of events, we could not identify any predictor of need for a PPM: pre-existing right bundle branch block (RBBB) (OR 2.72 [0.63-11.87], p=ns), use of a 29 mm prosthesis (OR 2.73 [0.33-22.90], p=ns) and left ventricular septal hypertrophy (OR 2.63 [0.08-83.32], p=ns). CONCLUSIONS In this cohort of patients treated with the CoreValve® Accutrak™ system, the incidence of permanent pacemaker implantation was low, which may be a consequence of an average small implantation depth. The Accutrak™ catheter seems to be helpful in achieving higher and more predictable implants. Operators could standardise their technique to place the CoreValve® prostheses less than 6 mm below the aortic annulus.