Bioprosthetic mitral valve thrombosis less than one year after replacement and an ablative MAZE procedure: a case report

Occurrence of bioprosthetic valve thrombosis less than a year after replacement is very uncommon. Here, we describe a case of a 57 year old male, who presented 10 months after receiving a bioprosthetic mitral valve replacement with a two week history of dyspnea on exertion, worsening orthopnea and decreased exercise tolerance. Echocardiography revealed severe mitral regurgitation (MR), thrombosis of the posterior mitral leaflet, left atrial (LA) mural thrombus and a depressed left ventricular ejection fraction of twenty-five percent. Given severe clot burden and decompensated heart failure (New York Heart Association - NYHA class III) repeat sternotomy was done to replace the bioprosthetic mitral valve and remove LA mural thrombus. MR was resolved postoperatively. This brief report further reviews promoting factors, established guidelines and management strategies of bioprosthetic valve thrombosis

Pretreatment with phenoxybenzamine attenuates the radial artery's vasoconstrictor response to α-adrenergic stimuli

AbstractBackgroundAlthough the radial artery bypass conduit has excellent intermediate-term patency, it has a proclivity to vasospasm. We tested the hypothesis that brief pretreatment of a radial artery graft with the irreversible adrenergic antagonist phenoxybenzamine attenuates the vasoconstrictor response to the vasopressors phenylephrine and norepinephrine compared with the currently used papaverine/lidocaine.MethodsSegments of human radial artery grafts were obtained after a 30-minute intraoperative pretreatment with a solution containing 20 mL of heparinized blood, 0.4 mL of papaverine (30 mg/mL), and 1.6 mL of lidocaine (1%). The segments were transported to the laboratory and placed into a bath containing Krebs-Henseleit solution and 10, 100, or 1000 μmol/L phenoxybenzamine or vehicle. The segments were tested in organ chambers for contractile responses to increasing concentrations of phenylephrine and norepinephrine (0.5-15 μmol/L).ResultsContractile responses to 15 μmol/L phenylephrine in control radial artery segments averaged 44.2% ± 9.1% of the maximal contractile response to 30 mmol/L KCl. Papaverine/lidocaine modestly attenuated contraction to 15 μmol/L phenylephrine (32.1% ± 5.9%; P = .22), but 1000 μmol/L phenoxybenzamine completely abolished radial artery contraction (−7.2% ± 4.4%; P < .001). The effect of 10 and 100 μmol/L phenoxybenzamine on attenuating vasocontraction was intermediate between 1000 μmol/L phenoxybenzamine and papaverine/lidocaine. Responses to 15 μmol/L norepinephrine in control radial artery segments averaged 54.7% ± 7.5% of maximal contraction to 30 mmol/L KCl. Papaverine/lidocaine modestly attenuated the contraction response of radial artery segments (35.6% ± 5.1%; P = .04). In contrast, 1000 μmol/L phenoxybenzamine showed the greatest attenuation of norepinephrine-induced contraction (−10.5% ± 2.0%; P < .001).ConclusionsA brief pretreatment of the human radial artery bypass conduit with 1000 μmol/L phenoxybenzamine completely attenuates the vasoconstrictor responses to the widely used vasopressors norepinephrine and phenylephrine. Papaverine/lidocaine alone did not block vasoconstriction to these α-adrenergic agonists

The impact of body mass index on morbidity and short- and long-term mortality in cardiac valvular surgery

ObjectiveLimited data exist on patients with cardiac cachexia or morbid obesity presenting for valvular heart surgery. The objective of this study was to investigate the relationship between body mass index and morbidity and mortality after valvular surgery.MethodsA retrospective review of 4247 patients undergoing valvular surgery from 1996 to 2008 at Emory University Healthcare Hospitals was performed. Patients were divided into 3 groups: body mass index 24 or less (group 1, n = 1527), body mass index 25 to 35 (group 2, n = 2284), and body mass index 36 or more (group 3, n = 436). Data were analyzed using multivariable regression analysis, adjusted for 10 preoperative covariates. A smooth kernel regression curve was generated using body mass index and in-hospital mortality as variables. Long-term survival comparisons were made using adjusted Cox proportional hazards regression models and Kaplan–Meier product-limit estimates. Kaplan–Meier curves were generated that provide survival estimates for long-term mortality using the Social Security Death Index.ResultsPatients in group 3 were significantly younger (group 1, 61.7 ± 16.1 years; group 2, 61.9 ± 13.6; group 3, 57.5 ± 13.0; P < .001) and more likely to be female (group 1, 778/1527 [51.0%]; group 2, 912/2284 [39.9%]; group 3, 240/436 [55.0%]; P < .001). Mean ejection fractions were similar among groups (P = .51). Patients in group 2 had significantly shorter postoperative length of stay (group 1, 9.6 ± 10.3 days; group 2, 8.7 ± 8.2 days; group 3, 10.8 ± 11.0 days; P < .001). In-hospital mortality for the entire cohort was 5.8% (245/4247), and by group was 111 of 1527 (7.3%) in group 1, 110 of 2284 (4.8%) in group 2, and 24 of 436 (5.5%) in group 3 (P = .006). Actual survival at 1, 3, 5, and 10 years was significantly lower in group 1 (P < .001). A lower body mass index was a significant independent predictor for both in-hospital and long-term mortality.ConclusionsPatients with body mass index 24 or less are at significantly increased risk of in-hospital and long-term mortality after cardiac valvular surgery. This high-risk patient population warrants careful risk stratification and options for less-invasive valve therapies

New-Onset Atrial Fibrillation Predicts Long-Term Mortality After Coronary Artery Bypass Graft

ObjectivesWe sought to investigate the association between new-onset atrial fibrillation after coronary artery bypass graft (CABG) (post-operative atrial fibrillation [POAF]) and long-term mortality in patients with no history of atrial fibrillation.BackgroundPOAF predicts longer hospital stay and greater post-operative mortality.MethodsA total of 16,169 consecutive patients with no history of AF who underwent isolated CABG at our institution between January 1, 1996, and December 31, 2007, were included in the study. All-cause mortality data were obtained from Social Security Administration death records. A multivariable Cox proportional hazards regression model was constructed to determine the independent impact of new-onset POAF on long-term survival after adjusting for several covariates. The covariates included age, sex, race, pre-operative risk factors (ejection fraction, New York Heart Association functional class, history of myocardial infarction, index myocardial infarction, stroke, chronic obstructive pulmonary disease, peripheral arterial disease, smoking, diabetes, renal failure, hypertension, dyslipidemia, creatinine level, dialysis, redo surgery, elective versus emergent CABG, any valvular disorder) and post-operative adverse events (stroke, myocardial infarction, acute respiratory distress syndrome, and renal failure), and discharge cardiac medications known to affect survival in patients with coronary disease.ResultsNew-onset AF occurred in 2,985 (18.5%) patients undergoing CABG. POAF independently predicted long-term mortality (hazard ratio: 1.21; 95% confidence interval: 1.12 to 1.32) during a mean follow-up of 6 years (range 0 to 12.5 years). This association remained true after excluding from the analysis those patients who died in-hospital after surgery (hazard ratio: 1.21; 95% confidence interval: 1.11 to 1.32). Patients with POAF discharged on warfarin experienced reduced mortality during follow-up.ConclusionsIn this large cohort of patients, POAF predicted long-term mortality. Warfarin anticoagulation may improve survival in POAF