Coronary atherectomy. Clinical, angiographic, and histological findings and observations regarding potential mechanisms.

Between August 5, 1988 and August 1, 1989, we attempted percutaneous directional coronary atherectomy of 76 lesions, including 42 primary lesions and 34 restenosis lesions that developed after one or more prior interventions. The procedure was successful in 67 lesions (88%), with a decrease in diameter stenosis from 80 +/- 11% to 5 +/- 15% after atherectomy (p less than 0.01). One or more complications occurred in six patients (9%), including non-Q wave myocardial infarction (three patients, 4.5%), femoral arterial injury requiring surgical repair (two patients, 3%), and proximal dissection leading to emergency bypass surgery (one patient, 1.5%). Despite these favorable acute results, the 6-month lesion restenosis rate was 30% by life-table analysis. Light microscopy of retrieved tissue revealed atherosclerotic plaque in 94%, media in 67%, and adventitia in 27%. Intimal proliferation was present in 97% of the restenosis lesions but was also evident in 33% of primary lesions. Tissue weight from 27 lesions averaged 18.5 mg (range, 5.8-45.1 mg), which is not adequate to explain the entire angiographic improvement. Thus, part of the improvement in lumen diameter appears to be due to mechanical dilatation rather than to tissue removal alone. Atherectomy can predictably treat selected coronary lesions with overall safety comparable to that of conventional balloon angioplasty, although the procedure as currently performed does not derive all of its benefit from tissue removal and does not appear to prevent restenosis.

Early coronary artery bypass grafting for complicated acute myocardial infarction.

The occurrence of unstable angina or cardiogenic shock after an acute myocardial infarction characterizes a subgroup of patients with increased morbidity and mortality. To assess the efficacy of surgical revascularization in this cohort, 96 patients who underwent coronary artery bypass grafting within 6 weeks of an acute myocardial infarction were compared to 485 patients who underwent myocardial revascularization without recent infarction. Fourteen (15%) of the patients with acute infarction were in cardiogenic shock and 82 (85%) patients had unstable angina at the time of surgery. Preoperatively, the patients with acute infarction compared to the patients without acute infarction were older (+3.5 years), had an increased incidence of congestive heart failure (21% vs 13%), and had a lower mean ejection fraction (4% vs 65%). Preoperative intraaortic balloon support was used in 9 patients (65%) with cardiogenic shock, and in 16 patients (19%) with unstable angina. Mean interval to surgery from time of infarction was 14.9 days. Overall operative mortality was 7.3% (7 patients) for the acute infarction group 28% for patients with cardiogenic shock and 3.7% for patients with unstable angina compared to 3.7% for the group of patients without recent infarction. Earlier surgical intervention did not result in a significant increase in operative mortality. Discriminant analysis of the recent infarction cohort demonstrated that preoperative ejection fraction less than 45% and age greater than 70 were the most significant predictors of early mortality. Of the 89 patients surviving surgery, actuarial survival was 97% at 3 years with no late infarctions. At follow-up 95% of survivors were NYHA Class I or II.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship of estrogen and progesterone receptors to prognosis in breast cancer.

To ascertain the role of estrogen (ER) and progesterone (PR) receptors as prognostic indicators of resectable breast cancer, the records of 204 patients were analyzed whose receptor studies were done at the Maimonides Medical Center from 1975 to 1983. All patients had radical or modified radical mastectomies and did not show any evidence of distant metastases at the time of operation. Median follow-up was 37 months. An additional 117 patients received some form of adjuvant therapy, mainly chemotherapy, and were analyzed separately. Life table analysis using the log rank test for measuring significance, and a Cox multivariate analysis was performed. At 48 months, 22% of the ER positive (ER+) group versus 33% of the ER negative (ER-) group had recurred as compared to 16% and 35% for the PR+ versus PR- groups, respectively. Life table analysis of the disease free interval (DFI) showed that the difference between the ER+ and ER- groups was not significant (p greater than 0.1), while the difference in DFI between the PR+ and PR- groups was significant (p less than 0.05). Multivariate analysis revealed that the most important factors in predicting the DFI were nodal status (p less than 0.001), tumor size (p less than 0.025), and progesterone receptor status (p less than 0.05). Estrogen receptor status was not found to be significant. In conclusion, PR- patients have a shorter DFI than PR+ patients and that PR status is a more valuable predictor of DFI than ER status.

Acute spinal cord ischemia: prevention of paraplegia with verapamil.

Although irreversible damage to the central nervous system has been considered inevitable after 6 min of circulatory deprivation, there has been evidence for almost 20 years that this may be the consequence of postischemic events. Recent investigations have implicated calcium-mediated phenomena as responsible for damage to neuronal cells in the reperfusion period. We studied the effect of verapamil on the neurologic sequelae of spinal cord ischemia using somatosensory evoked potential monitoring in a canine preparation of spinal cord ischemia. Ten mongrel dogs weighing between 20 and 30 kg each were divided into two groups. The experimental group was pretreated with 0.4 mg/kg verapamil and the control group received no treatment. The thoracic aorta was then occluded. Flow was restored 17 min after there was complete loss of somatosensory evoked potentials. Experimental dogs received additional doses of verapamil upon reperfusion and at 1, 2, 3, 4, 5, 6, and 10 hr after reperfusion. Four of five verapamil-treated dogs were able to walk postoperatively, whereas all of the control dogs suffered dense paraplegias (p = .02). We conclude that verapamil can ameliorate the sequelae of spinal cord ischemia and that this preparation is suitable for the study of the mechanisms of ischemic neuronal damage in an area outside the brain.

Surgical results for mitral regurgitation from coronary artery disease.

Results of coronary artery bypass grafting with and without mitral valve replacement were analyzed retrospectively in 101 patients with preoperative ischemic mitral regurgitation to determine the effects of severity and surgical treatment of mitral regurgitation on survival. Between 1980 and 1984, a total of 1,475 patients (mean age 59, 77% male) underwent coronary bypass. These patients were divided into three groups: (1) patients without ischemic mitral regurgitation who underwent isolated coronary bypass (1,374; 93%), (2) patients with ischemic mitral regurgitation who underwent isolated coronary bypass without valve replacement (85; 6%), and (3) patients with ischemic mitral regurgitation who underwent combined mitral valve replacement and coronary bypass (16; 1%). Preoperatively, patients with ischemic mitral regurgitation compared to those without regurgitation were significantly older (+6 years, p less than 0.001), had more severe coronary artery disease (p less than 0.001), a higher incidence of congestive heart failure (24% versus 5%, p less than 0.001) and recent myocardial infarction (16% versus 8%, p less than 0.01), and a lower mean ejection fraction (45% versus 61%, p less than 0.001). Operative mortality was significantly increased in patients with ischemic mitral regurgitation who underwent coronary bypass alone (p less than 0.01) and in those who underwent coronary bypass and mitral valve replacement (p less than 0.01)--11% and 19%, respectively--than in the coronary bypass patients without ischemic mitral regurgitation (3.7%). The severity of mitral regurgitation (0 to 4+) proved to be the most significant predictor of operative mortality. The actuarial survival rate at 5 years for the coronary bypass patients without ischemic mitral regurgitation was 85% compared to 91% (p less than 0.05) for the coronary bypass patients without ischemic mitral regurgitation. These results indicate that patients with ischemic mitral regurgitation have a higher prevalence of cardiac risk factors and are at an increased risk of operative mortality. Although the severity of the ischemic mitral regurgitation was strongly predictive of early survival, it proved to have an unexpectedly modest effect on long-term survival after surgical treatment.