Faculty Bibliography

Coronary artery disease (CAD) is the leading cause of death in the United States. Although progression of CAD can be controlled using drugs and diet, it is usually detected in advanced stages when invasive treatment is required. Current methods to detect CAD are invasive and/or costly, hence not suitable as a regular screening tool to detect CAD in early stages. Currently, we are developing a noninvasive and cost-effective system to detect CAD using the acoustic approach. This method identifies sounds generated by turbulent flow through partially narrowed coronary arteries to detect CAD. The limiting factor of this method is sensitivity to noises commonly encountered in the clinical setting. Because the CAD sounds are faint, these noises can easily obscure the CAD sounds and make detection impossible. In this paper, we propose a method to detect and eliminate noise encountered in the clinical setting using a reference channel. We show that our method is effective in detecting noise, which is essential to the success of the acoustic approach.

Immigrants from the former Soviet Union have a higher prevalence of cardiac risk factors and more problems obtaining health care in the United States than American-born Caucasians. This study compared differences between patients of these two populations admitted for diagnosis of chest pain or shortness of breath. Immigrants from the former Soviet Union (who had been in the U.S. for an average of 20 years) had more cardiac risk factors than American-born Caucasians including more hypertension (81% vs. 50%, p=.002), positive family history (53% vs. 30%, p=.030), more previous heart attacks (45% vs. 20%, p=.012), more prior cardiac catheterizations (51% vs. 18%, p<.001) and coronary revascularization procedures (51% vs. 27%, p=.022), and higher systolic blood pressure (138+/-13 vs. 129+/-23 mmHg, p=.019) upon presentation to the hospital. Fifty-five percent of immigrant patients used foreign medications. Thus, there are major differences between immigrants from the former Soviet Union who are admitted to the cardiac units of an urban New York hospital and American-born Caucasians. Knowledge of these differences is important for caregivers.

Randomized trials have demonstrated the superiority of primary angioplasty with stent implantation over balloon angioplasty alone in the treatment of acute myocardial infarction (AMI). However, it remains unknown whether the beneficial outcomes that are attained in clinical trials can be generalized to community-based practice. We conducted a retrospective cohort study of all patients who underwent primary angioplasty for AMI in New York State in 1998 and 1999. In total, 6,010 consecutive patients who presented within 23 hours of an AMI were identified for this analysis. In-hospital mortality was the primary end point. Stents were placed in 5,225 patients (87%). Patients who received stents were younger (61 vs 62 years, p = 0.011) and less often women (29% vs 33%, p = 0.018). Patients who received stents were less likely to have a history of hypertension (56% vs 61%, p = 0.013), diabetes (17% vs 24%, p <0.001), a creatinine level > or = 2.5 mg/dl (0.8% vs 2.0%, p = 0.002), 3-vessel coronary disease (14% vs 19%, p <0.001), and left main disease (2.4% vs 4.6%, p <0.001). Stent use was associated with significant decreases in length of stay (5.9 vs 8.1 day, p <0.001), major adverse cardiovascular events (4.1% vs 12%, p <0.001), and in-hospital mortality (3.5% vs 9.3%, p <0.001). After multivariate logistic regression analysis to adjust for differences in baseline characteristics, stent use was associated with a 50% decrease in risk of in-hospital mortality (odds ratio 0.474, 95% confidence interval 0.311 to 0.723, p = 0.001)