Objective Delivery of a collapsable aortic valve prosthesis via the left ventricular (LV) apex has proven problematic clinically. We describe our experience with a novel technique for a laparoscopic transdiaphragmatic approach to the LV outflow tract (LVOT). Methods Laparoscopic transabdominal access to the left ventricle was achieved in four live swine and one human cadaver using three abdominal laparoscopic trocars. Pericardioscopy and cardioscopy were performed. A hemostatic purse-string suture was placed laparoscopically at the apex of the left ventricle in one pig, and an instrument passed through the purse-string and into the LVOT. After the procedure, a thoracotomy was performed and the heart explanted for gross examination. Results Transdiaphragmatic exposure of the LV apex was accomplished at a mean of 23 minutes. Hemodynamic stability was maintained in all animals and the pleural cavities were not violated. Pericardioscopy allowed visualization of both right and left pulmonary veins along with the left atrial appendage. In situ cardioscopy confirmed that access to the LVOT and the aortic annulus was possible from the LV apex entry site. Conclusions Laparoscopic transdiaphragmatic approach to the LVOT is a possible route for minimally invasive beating heart aortic valve implantation. This strategy permits a straight transapical line of access to the aortic valve; avoiding the potential for cardiac torsion via a thoracotomy.
Clinical Outcome After Surgical Correction of Mitral Regurgitation Due to Papillary Muscle Rupture
Background— Papillary muscle rupture (PMR) is an infrequent but catastrophic complication of acute myocardial infarction (MI). Although always considered, surgical treatment is often denied because of high operative mortality. Moreover, the effects of surgery for PMR on long-term outcome, particularly compared with expected outcome after MI, are undefined. Methods and Results— Fifty-four consecutive patients (age, 70±8 years; 74% male) underwent mitral surgery for post-MI PMR from January 1980 through December 2000. Severe presentation (cardiogenic shock, pulmonary edema, or cardiac arrest) was noted in 91% preoperatively. Performance of coronary artery bypass graft was associated with lower operative mortality (odds ratio, 0.18; 95% CI, 0.04 to 0.83; P =0.011), whereas there was a trend for lower mortality after surgery after 1990 (odds ratio, 0.28; 95% CI, 0.06 to 1.3). Thus, operative mortality (overall, 18.5%) decreased from 67% up to 1990 without coronary artery bypass graft to 8.7% after 1990 with coronary artery bypass graft. Overall 5-year survival was 65±7%, and survival free of congestive heart failure was 52±7%. Five-year survival of 30-day operative survivors was 79±4%, identical ( P =0.24) to that of matched controls with MI (similar age, sex, ejection fraction, MI location, and MI year). Survival free of congestive heart failure was similar in PMR cases and MI controls (10-year survival, 28±8% versus 36±6%; P =0.46). Conclusions— Surgery for post-MI PMR involves a notable operative mortality, but there are recent trends for lower operative risk, particularly with associated coronary artery bypass graft. Long term after surgery, outcome is restored to that of similar MI without PMR. These encouraging observations emphasize the importance of prompt diagnosis and aggressive therapeutic approach for patients incurring PMR after MI.
Mayo Clinic Risk Score for Percutaneous Coronary Intervention Predicts In-Hospital Mortality in Patients Undergoing Coronary Artery Bypass Graft Surgery
Background— Current risk models predict in-hospital mortality after either coronary artery bypass graft surgery or percutaneous coronary interventions separately, yet the overlap suggests that the same variables can define the risks of alternative coronary reperfusion therapies. Our goal was to seek a preprocedure risk model that can predict in-hospital mortality after either percutaneous coronary intervention or coronary artery bypass graft surgery. Methods and Results— We tested the ability of the recently validated, integer-based Mayo Clinic Risk Score (MCRS) for percutaneous coronary intervention, which is based solely on preprocedure variables (age, creatinine, ejection fraction, myocardial infarction ≤24 hours, shock, congestive heart failure, and peripheral vascular disease), to predict in-hospital mortality among 370 793 patients in the Society of Thoracic Surgeons database undergoing isolated coronary artery bypass graft surgery from 2004 to 2006. For the Society of Thoracic Surgeons coronary artery bypass graft surgery population studied, the median age was 66 years (quartiles 1 to 3, 57 to 74 years), with 37.2% of patients ≥70 years old. A high prevalence of comorbid conditions, including diabetes mellitus (37.1%), hypertension (80.5%), peripheral vascular disease (15.3%), and renal disease (creatinine ≥1.4 mg/dL; 11.8%), was present. A strong association existed between the MCRS and the observed mortality in the Society of Thoracic Surgeons database. The in-hospital mortality ranged between 0.3% (95% confidence interval 0.3% to 0.4%) with a score of 0 on the MCRS and 33.8% (95% confidence interval 27.3% to 40.3%) with an MCRS score of 20 to 24. The discriminatory ability of the MCRS was moderate, as measured by the area under the receiver operating characteristic curve (C-statistic=0.715 to 0.784 among various subgroups); performance was inferior to the Society of Thoracic Surgeons model for most categories tested. Conclusions— This model, which is based on 7 preprocedure risk variables, may be useful for providing patients with individualized, evidence-based estimates of procedural risk as part of the informed consent process before percutaneous or surgical revascularization.