Left atrial appendage exclusion and the risk of thromboembolic events following mitral valve surgery.

OBJECTIVES: We aimed to evaluate left atrial appendage (LAA) exclusion in patients undergoing mitral valve surgery with respect to thromboembolic events. BACKGROUND: LAA is the predominant source of emboli in patients with atrial fibrillation. Prophylactic LAA exclusion at the time of heart surgery has been recommended to reduce the risk of future thromboembolism. METHODS: An observational cohort of 136 patients undergoing LAA exclusion during mitral valve surgery was identified between May 1993 and November 1998 at our institution. RESULTS: During a mean follow-up of 3.6 +/- 1.3 years, there were 14 (12.3%) thromboembolic events. Compared with patients who received warfarin upon hospital discharge, there were more thromboembolic events in patients not prescribed warfarin upon hospital discharge (n = 7/67, 10% vs n = 6/40, 15%, respectively). The warfarin status was not known for one patient. The majority of thromboembolic events (n = 10/14, 71%) occurred in those who underwent mitral valve repair. CONCLUSION: In this observational study, patients who undergo LAA exclusion during mitral valve surgery to reduce the risk of thromboembolism have a significant incidence of thromboembolic events, especially when warfarin therapy is not prescribed upon hospital discharge.

An angiographic and intravascular ultrasound study of the left anterior descending coronary artery in takotsubo cardiomyopathy.

The precise cause of takotsubo cardiomyopathy (TC) remains controversial. Plaque rupture with transient thrombotic occlusion of a transapical left anterior descending coronary artery (LAD) has been advanced as a potential mechanism. To explore this hypothesis, the investigators analyzed data from 11 patients prospectively enrolled in the Rhode Island Takotsubo Cardiomyopathy Registry who underwent coronary angiography and intravascular ultrasound evaluation of the LAD during their initial presentation. Despite the presence of nonobstructive coronary artery disease, no culprit lesion was identified in any patient. Similarly, the course of the LAD failed to account for the characteristic left ventricular apical ballooning seen in TC. In conclusion, an atherosclerotic coronary lesion in the LAD causing an aborted myocardial infarction may not be the primary underlying cause of TC, and nonobstructive coronary artery disease and TC may coexist without a direct causal association.

Clinical characteristics and four-year outcomes of patients in the Rhode Island Takotsubo Cardiomyopathy Registry.

The aim was to establish a registry of patients with a diagnosis of Takotsubo cardiomyopathy (TC) to help learn more about the characteristics, treatment strategies, and natural history of this disease. Data for patients with TC diagnosed from July 2004 to April 2008 at 2 major hospitals in Rhode Island were obtained. A data set was created that included baseline demographics and characteristics, hospital, course, and clinical outcomes. TC was diagnosed in 70 patients during the study period. Postmenopausal women comprised 95% of the cohort. Six patients presented with cardiogenic shock, 9 required intubation, 3 experienced sustained ventricular arrhythmias, and 1 patient died of cardiac causes. Average ejection fraction was 37% at cardiac catheterization. Troponin-I was increased in all except 1 patient. Follow-up echocardiography showed full recovery of wall motion abnormalities, with an average ejection fraction of 59%. Most patients were treated using standard cardiovascular medications for acute coronary syndrome, and 43% were discharged on warfarin therapy because of severe apical wall motion abnormalities. Univariate analysis suggested that long-term use of angiotensin-converting enzyme inhibitors before the onset of TC was protective against cardiogenic shock, sustained ventricular arrhythmia, and death. Consecutive cases grouped into different seasons showed a statistically significant spike in the occurrence of TC during the summer months. In conclusion, the acute phase of this condition may lead to critical illness and death, and use of an angiotensin-converting enzyme inhibitor may have a protective effect. Overall long-term prognosis and recovery of left ventricular function were excellent.