James L. Vacek

Exercise echocardiography as a screening test for coronary artery disease and correlation with coronary arteriography

We evaluated exercise echocardiography as a screening test for coronary artery disease in 228 patients, all of whom underwent subsequent coronary angiography. After an echocardiogram at rest was obtained, each patient performed maximal, symptom-limited, upright treadmill exercise, immediately after which repeat imaging was performed. The exercise echocardiogram was abnormal if any segment failed to become hypercontractile with exercise, and these regional wall motion abnormalities were used to predict the extent and distribution of coronary disease. At subsequent angiography, coronary stenosis was defined as significant if luminal diameter was reduced greater than or equal to 50%. Compared with electrocardiography, exercise echocardiography was more sensitive (97 vs 51%) and specific (64 vs 62%), and had higher positive (90 vs 82%) and negative (87 vs 28%) predictive accuracies. Exercise echocardiography was also highly predictive of the extent (no, 1-, 2- or 3-vessel disease) and distribution (which vessel) of coronary stenoses. It is concluded that exercise echocardiography is an excellent screening test for the presence, extent and distribution of coronary artery disease.

Angioplasty versus bypass surgery for multivessel coronary artery disease with left ventricular ejection fraction ≤40%☆

Patients with multivessel coronary artery disease and left ventricular dysfunction represent a high-risk subgroup in whom coronary artery bypass grafting has been shown to improve survival compared with that of medically treated patients. The comparative benefits and risks of coronary angioplasty and bypass surgery in this subgroup of patients are unclear. This study retrospectively analyzes 100 consecutive patients treated with bypass surgery compared with a matched, concurrent cohort of 100 treated with multivessel angioplasty. Early results favored angioplasty; a hospital stay of 12.8 days was noted in the bypass group compared with 4.3 days in the angioplasty group (p < 0.001). In-hospital mortality rates were similar in the bypass (5%) and angioplasty (3%) groups (p = NS). Stroke was observed significantly more often in the bypass group (7 vs 0%). However, late follow-up favored bypass patients; repeat revascularization procedures and late myocardial infarction occurred more frequently during follow-up in the angioplasty group. During 5-year follow-up, superior relief from disabling angina (99 vs 89%; p = 0.01) and a trend toward improved survival (76 vs 67%; p = 0.09) were observed in the bypass group as compared with the angioplasty group. Multivariate correlates of late mortality included age and incomplete revascularization, but not mode of revascularization. Thus, in patients with multivessel coronary artery disease and left ventricular dysfunction, early results favor angioplasty, whereas late follow-up favors bypass surgery. However, late survival was similar in both groups of patients who were completely revascularized.

Comparison of Lovastatin (20 mg) and Nicotinic Acid (1.2 g) With Either Drug Alone for Type II Hyperlipoproteinemia

Our study indicates that the combination of nicotinic acid (1.2 g/day) and lovastatin (20 mg/day) is more effective than either drug alone in reducing total and LDL cholesterol. Although HDL cholesterol was not significantly improved by these doses of agents over the duration of this study, LDL/HDL and HDL/total cholesterol ratios were improved due to the beneficial actions on total and LDL cholesterol. No serious side effects or changes in serum chemistries were observed, and the combination was well tolerated.

Coronary angioplasty versus bypass surgery in patients >70 years old matched for ventricular function☆

OBJECTIVES This study compared the relative risks and benefits of coronary angioplasty and coronary artery bypass graft surgery in patients > 70 years old. BACKGROUND Few objective, comparative data exist to guide the clinician in the decision to use bypass surgery or angioplasty in elderly patients. METHODS The study was a case-control, retrospective analysis of 195 consecutive patients who underwent bypass surgery in 1987 and 1988 and were compared with a concurrent cohort of 195 coronary angioplasty-treated patients. The groups were matched for left ventricular function, age and gender mix. RESULTS The in-hospital morbidity and mortality rates were significantly lower in the coronary angioplasty-treated patients. Mean postprocedural hospital stay was 4.8 and 14.3 days for angioplasty and surgical group patients, respectively (p < 0.001). In-hospital death occurred in 2% of angioplasty-treated patients compared with 9% of surgically treated patients (p = 0.007). Serious in-hospital stroke occurred in no patient in the angioplasty group and in 5% of patients in the surgical group (p < 0.0001). Q wave infarction occurred in 1% of angioplasty-treated patients and 6% of bypass-treated patients (p = 0.01). The 5-year actuarial survival rate was similar in the two groups: 63% in the angioplasty group, 65% in the bypass group (p = NS). However, surgical group patients experienced less recurrent angina, required fewer repeat revascularization procedures and had fewer Q wave infarctions during follow-up compared with angioplasty group patients. CONCLUSIONS When performed in patients > 70 years old, angioplasty and coronary bypass surgery result in similar long-term survival rates but otherwise distinctly different clinical courses.

Exercise echocardiography after coronary artery bypass grafting

Exercise echocardiography was used to assess the adequacy of regional myocardial perfusion in 125 patients who had undergone coronary artery bypass grafting. There were 108 men and 17 women (mean age 65 years) evaluated from 6 weeks to 16 years (mean 7 years) after surgery. Resting parasternal long- and short-axis and apical 4- and 2-chamber echocardiograms were recorded, digitized and stored. Maximal, symptom-limited upright treadmill exercise was then performed with continuous electrocardiographic monitoring. Repeat echocardiographic imaging and digitization were repeated within 1 minute of exercise termination. Resting and postexercise digitized echocardiograms were compared. A normal regional wall motion response to exercise consisted of improved segmental contraction and was used to predict uncompromised regional vascular supply. Unimproved or worsened segmental contraction after exercise was abnormal and was used as a predictor of regional vascular insufficiency. All patients underwent cardiac catheterization within 1 month after exercise testing. Regional coronary insufficiency was considered to exist when a segments major vascular conduit exhibited greater than or equal to 50% luminal diameter reduction. Compared with the simultaneously acquired stress electrocardiogram, exercise echocardiography had superior sensitivity (98 vs 41%), specificity (92 vs 67%), positive predictive value (99 vs 91%), and negative predictive value (86 vs 12%) (p less than 0.001, 0.1, 0.01 and less than 0.001, respectively). In addition, exercise echocardiography correlated closely with the extent and regional distribution of compromised vascular supply. Exercise echocardiography is a highly sensitive, specific and accurate screening test for abnormal global and regional myocardial vascular supply in patients who have undergone coronary artery bypass grafting.

Sex-related differences in patients undergoing direct angioplasty for acute myocardial infarction

Important sex-related differences have been recognized in several coronary artery disease presentation and treatment subsets. Little data exist describing the relative findings and outcome in women versus men who received direct percutaneous transluminal coronary angioplasty for acute myocardial infarction. We studied 670 such patients of whom 464 (69%) were men and 206 were women. The women were significantly older (67 +/- 11 years vs 61 +/- 11, p < 0.001) but had undergone less prior coronary artery bypass graft surgery (6% vs 12%, p = 0.02), whereas prior myocardial infarction (17% women vs 22% men) and coronary artery disease distribution were not significantly different. Forty-one percent of women and 43% of men had single-vessel disease (p = NS). Both women and men had 1.5 lesions/patient dilated acutely, with similar success rates (95% women, 91% men; p = 0.08). Mean ejection fractions were similar (48% in both groups), and a similar percentage in each group had an ejection fraction < 30% (10% women vs 13% men). Over a mean follow-up period of 86 weeks, the need for repeat catheterization was frequent and was similar in both groups (44% women, 47% men; p = NS), whereas documented restenosis was less common in women (20% vs 28% of patients, p < 0.05). The need for coronary artery bypass grafting was similar (15% women, 17% men; p = NS), as was the need for repeat percutaneous transluminal coronary angioplasty in the infarct vessel (14% women, 18% men; p = NS) and overall mortality (7% women, 9% men; p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Use of intravenous adenosine as a noninvasive diagnostic test for sick sinus syndrome

BACKGROUND Testing for sick sinus syndrome (SSS) requires invasive stimulation protocols for sinus node recovery time (SNRT) and corrected sinus node recovery time (CSNRT). METHODS AND RESULTS We compared the CSNRT with the lengthening of the sinus cycle length (ADO:SCL) corrected to the basic cycle length (ADO:CSNRT) after administration of an intravenous bolus of adenosine (0.15 mg/kg) in 10 patients with clinical SSS (group 1) and 67 control patients (group 2). With 550 ms as an abnormal result for the ADO:CSNRT (and for the CSNRT) as an indicator of sinus node dysfunction, the ADO:CSNRT had a sensitivity of 80% and specificity of 97% for detection of SSS compared with sensitivity and specificity of 70% and 95% for invasive CSNRT. When combined, the 2 tests had a sensitivity of 100%. There was significant difference in the CSNRT between group 1 (1848 +/- 1825 ms) and group 2 (355 +/- 169 ms, P <. 0001) and a significant difference in ADO:CSNRT between group 1 (1168 +/- 1002 ms) and group 2 (272 +/- 592 ms, P <.0001). CONCLUSIONS We conclude that the ADO:CSNRT is a sensitive and specific test for SSS that equals invasive testing and should be considered as an alternative to invasive testing in patients with suspected SSS.

Management comparison for acute myocardial infarction: Direct angioplasty versus sequential thrombolysis-angioplasty

To compare the results and outcome of different management approaches for acute myocardial infarction, we analyzed our experience with early (i.e., within 6 hours of infarct onset) direct percutaneous transluminal coronary angioplasty (group A) versus initial treatment with thrombolytic therapy (group B) followed by angioplasty. From 1982 to 1989 a total of 214 patients underwent primary angioplasty for acute myocardial infarction. During this time 157 patients underwent initial thrombolytic therapy, 104 with intravenous streptokinase and 53 with intravenous tissue-type plasminogen activator followed by angioplasty. Other than age (group A, 61.7 +/- 11.5 years; group B, 57.3 +/- 11.6 years; p = 0.0002), the clinical characteristics of the groups were similar. In group A, 197 (92.1%) had successful results, and 17 (7.9%) were failures. Of the group treated with thrombolytic therapy, there was an overall 81.5% patency rate for patients treated with streptokinase and tissue-type plasminogen activator with no significant difference between the agents. Angioplasty success after thrombolytic therapy was 94.3%. In-hospital and 1-year survival was significantly better in group B patients (95.5% and 95.5%, respectively) than in group A patients (92.1% and 89.3%, respectively). We conclude that both direct angioplasty and thrombolytic therapy followed by angioplasty provide high recanalization rates but that short- and long-term survival is improved when thrombolytic therapy precedes angioplasty in acute myocardial infarction patients.

Use of exercise echocardiography to evaluate patients after coronary angioplasty

Exercise echocardiography is a sensitive, specific, and highly accurate method for detecting coronary restenosis and progressive compromise of untreated arterial segments in patients who have undergone percutaneous transluminal coronary angioplasty. It is far more reliable in predicting the status of the coronary anatomy in such patients than exercise electrocardiography or symptomatic status.

Validation of a bedside method of activated partial thromboplastin time measurement with clinical range guidelines

Abstract Rapid measurement of an anticoagulant effect due to heparin is desirable in a variety of settings. Patients with cardiovascular diseases undergo heparinization for many reasons including management of unstable angina, in conjunction with thrombolytic therapy for myocardial infarction, percutaneous transluminal coronary angioplasty, extracorporeal bypass, atrial fibrillation with perceived embolic risk, prosthetic heart valves and several variants of cerebral vascular disease. 1–9 Standard clinical laboratory measurements of partial thromboplastin time (PTT) are cumbersome and slow, and prone to multiple potential sources of error. 2–4,10–13 To provide a rapid, simple, accurate bedside means of PTT measurement, the Hemochron system was used to assess a means of automated immediate analysis. We assessed the utility of this system in the cardiac catheterization laboratory by comparing PTT measurements derived from this technique with activated clotting times (ACT) in patients undergoing cardiac catheterization and angioplasty both before and after the procedure.