Faculty Bibliography

Exercise duration during exercise treadmill testing (ETT) predicts long-term outcome among asymptomatic patients with mitral regurgitation. However, the prognostic value of preoperative exercise duration in patients who undergo mitral valve surgery is unknown. We examined findings among 45 prospectively followed (average 9.2 +/- 4.3 years) patients (aged 54.8 +/- 12.0 years, 45% men) with chronic isolated severe MR who underwent ETT before mitral valve surgery to test the hypotheses that exercise duration predicts long-term postoperative survival and persistent symptoms within 2 years after operation. During follow-up, 11 patients died; of these, 8 had persistent symptoms. Among patients who exercised >7 minutes, average annual postoperative all-cause and cardiovascular mortality risks were 0.75% (both endpoints) versus 5.4% and 4.8%, respectively, versus those who exercised /=II) symptom persistence (p = 0.012), whereas other ETT, echocardiographic and clinical variables did not (NS, all). In conclusion, among patients who undergo surgery for chronic nonischemic mitral regurgitation, preoperative exercise duration, unlike many commonly used descriptors, is useful for predicting postoperative mortality and symptom persistence. Future research should determine whether interventions to improve exercise tolerance before mitral valve surgery can modify these postoperative outcomes.

Total occlusion of the left main coronary artery predominantly presents with recurrent angina or myocardial infarction. Long-term survival and myocardial function depends on the well-developed right to left collaterals. We report a case of a 46-year-old man who was referred because of incidental finding of low ejection fraction during work-up for syncope 5 months prior. The patient denied any recurrence or any other symptom after that episode and claimed an unchanged exercise capacity. He had hypertension, hyperlipidemia, and history of 15-pack/year smoking. Except for class II morbid obesity, he had completely normal vital signs, physical examination, and lab tests on admission. The echocardiogram was suggestive of previous anterior wall myocardial infarction and demonstrated a low left ventricle ejection fraction with diffuse hypokinesis of the left ventricle. The patient underwent cardiac catheterization, which revealed total occlusion of the left main coronary artery, dominant right coronary artery with a 95% stenosis in the proximal segment, and collaterals from the right to the left coronary arteries. The patient was immediately referred for coronary artery bypass surgery. This case demonstrates the power of collateral circulation in protecting the patient from symptoms and death despite total occlusion of the left main coronary artery and severe stenosis of the proximal right coronary artery.