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Biomedical subjects

J L Vacek

Publications and source records attributed to J L Vacek.

At least 37 records · Page 2Linked to original sources
PubMed1995

Timing, mode, and predictors of death after direct angioplasty for acute myocardial infarction.

The timing and mechanisms of early (30 day) mortality in 330 consecutive patients treated with direct angioplasty less than 12 hr after onset of myocardial infarction without antecedent thrombolysis were studied. There were 38 deaths (11.5% of pts), with a majority being due to cardiogenic shock (76%). Other causes included acute closure (11%), death after emergency bypass surgery (5%), ventricular arrhythmias (5%), and respiratory failure (3%). No deaths from stroke or cardiac rupture were seen, in contrast to trials of thrombolytic agents. Most deaths were seen early, with 47% occurring within 1 day, 35% from days 2-7, and 18% from days 8-30. Death from cardiogenic shock was the most common cause of death throughout this period: 83% of deaths in days 0-3, 88% of deaths in days 4-6, and 43% of deaths in days 8-30. Significant predictors of early death included older age (P < .0001), multi-vessel disease (P < .05), direct angioplasty failure (P < .05), reduced ejection fraction (P < .0001), and anterior myocardial infarction (P < .0005). Gender, prior myocardial infarction, and prior bypass surgery did not affect mortality. Cardiogenic shock is the most common cause of early death after direct angioplasty for myocardial infarction. Patients with one or more risk factors for early death may benefit from additional myocardial salvage or revascularization efforts in the early post-infarct period. Certain causes of death after direct angioplasty (cardiac, rupture, stroke) appear to be less common than data reported for lytic therapy for myocardial infarction.

Adult↗
PubMed1995

Peripheral arterial disease. When to consider percutaneous revascularization.

Currently, percutaneous revascularization techniques are recommended for peripheral arterial disease only when limiting or disabling symptoms are present. However, the cost of these procedures is less than that of surgery and the risk is much lower. Additional prospective, randomized studies are needed for better definition of the role of percutaneous techniques in clinical practice. In the future, as techniques evolve and outcomes become better defined, this role may be expanded.

Angioplasty, Balloon↗
PubMed1994

Dobutamine stress echocardiography: clinical utility and predictive value at various infusion rates.

Dobutamine stress echocardiography has increasingly been used to assess patients for coronary artery disease. Despite the popularity of this test, the optimal dose of dobutamine has not been established. The objective of this study was to assess the accuracy of dobutamine stress echocardiography at various infusion doses and its utility as a predictor of perioperative risk in patients undergoing a noncardiac surgical procedure. One hundred thirteen consecutive patients underwent dobutamine stress echocardiography, subsequent cardiac catheterization and/or a noncardiac surgical procedure. Three patient groups were analyzed on the basis of peak dobutamine infusion rates (17 +/- 4, 29 +/- 2, and 40 +/- 0 micrograms/kg/min, respectively). The three groups were comparable with regard to age, sex, ejection fraction, and severity of coronary artery disease. In group I, the sensitivity and specificity of dobutamine stress echocardiography were 74% and 33%, respectively, with a positive predictive value of 78%. In group II, the sensitivity and specificity improved to 84% and 78%, with a positive predictive value of 89%. In group III, the sensitivity and specificity were 86% and 80%, respectively, with a positive predictive value of 86%. In the noncardiac surgical group there was only one nonfatal cardiac complication among the 50 patients with a dobutamine echocardiogram, which was negative for evidence of inducible ischemia. In conclusion, this study demonstrates that dobutamine stress echocardiography should use an infusion rate of > or = 30 micrograms/kg/min to optimize diagnostic accuracy relative to angiographic coronary artery disease. A test that shows no evidence of new, inducible ischemia predicts a low risk of perioperative cardiac events in patients undergoing noncardiac surgery, even at an infusion rate as low as 20 microns/kg/min.

Aged↗
PubMed1994

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.

Actuarial Analysis↗
PubMed1994

Angioplasty versus thrombolysis for acute myocardial infarction.

Both direct angioplasty and thrombolytic therapy can decrease mortality from acute myocardial infarction, but certain subgroups of patients benefit more from one method than the other. Direct angioplasty is favored in patients in cardiogenic shock (with perhaps the exception of those who are elderly or have three-vessel coronary disease) and patients who have undergone previous coronary bypass surgery. Thrombolytic therapy and direct angioplasty seem to be equally effective in patients with acute myocardial infarction who present more than 6 hours after onset of symptoms or have multivessel coronary artery disease. The location of the infarct (anterior versus inferior) does not favor one therapy over the other. We believe that in most patients, the best approach is to begin with thrombolytic therapy and to follow that with selective application of angioplasty when it is clinically appropriate.

Aged↗
PubMed1994

Adjunctive medical therapy for acute myocardial infarction.

Physicians should consider oxygen, morphine, nitrates, beta blockers, and aspirin as the foundation of early adjunctive treatment of acute myocardial infarction. An angiotensin-converting enzyme (ACE) inhibitor should be considered after 72 hours of adjunctive treatment. Intravenous heparin therapy is useful in certain subsets of patients, and intravenous magnesium therapy shows promise. With the exception of beta blockers, prophylactic antiarrhythmic agents are currently not indicated. We predict that combination therapy with aspirin, a beta blocker, and an ACE inhibitor will assume an ever-increasing role in treatment of myocardial infarction.

Adrenergic beta-Antagonists↗
PubMed1994

Thrombolytic therapy for acute myocardial infarction. Are inclusion criteria too stringent?

There is little question that reperfusion therapy with thrombolytic agents benefits patients who meet the current eligibility requirements and receive therapy shortly after acute myocardial infarction. Less clear is whether this therapy would benefit and be safe for use in patients who are now deemed ineligible to receive it. The authors compare the three available intravenous thrombolytic agents, summarize the risks and benefits associated with thrombolytic therapy in various situations, and make recommendations based on their experience.

Anistreplase↗
PubMed1993

Comparison of results of coronary angioplasty during acute myocardial infarction with and without previous coronary bypass surgery.

Six hundred one consecutive patients undergoing reperfusion within 6 hours of acute myocardial infarction were studied with regard to impact of previous coronary artery bypass grafting (CABG) on direct coronary angioplasty performance and results. Forty-nine patients (8%) had previously undergone CABG, whereas 552 (92%) had not. Direct angioplasty was used for reperfusion in 35 patients (71%) in the CABG group, and in 258 (47%) in the non-CABG group (p < 0.01). No significant differences between these groups were noted with regard to gender, age, infarction site, time to reperfusion or angioplasty success (34 of 35 CABG patients [97%] vs 236 of 258 non-CABG patients [92%]). CABG patients were more likely to have had previous infarction (17 of 35 [49%] vs 35 of 258 [14%] [p < 0.001]), multivessel disease (34 of 35 [97%] vs 127 of 258 [49%] [p < 0.001]) and lower mean ejection fraction (0.36 +/- 0.13 vs 0.46 +/- 0.12, p < 0.001). Over a mean follow-up of 151 weeks, 24 patients (69%) in the CABG group were restudied versus 112 (43%) in the non-CABG group (p < 0.01). Restenosis occurred in 14 patients (40%) in the CABG group versus 58 (22%) in the group without previous CABG (p = 0.04). In the CABG group, restenosis occurred significantly more often in saphenous vein grafts than in native vessels (12 of 17 [71%] vs 2 of 11 [18%] [p < 0.02]). There was no significant difference in the overall performance of repeat angioplasty between the 2 groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Angioplasty versus bypass surgery for multivessel coronary artery disease with left ventricular ejection fraction < or = 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.

Actuarial Analysis↗
PubMed1993

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)

Aged↗
PubMed1993

Effects of angiotensin-converting enzyme inhibitor therapy on presence of late potentials detected using signal-averaged electrocardiography in patients with congestive heart failure.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors have been shown to improve the mortality rate in patients with congestive heart failure. The exact mechanism of this effect is uncertain. Signal-averaged electrocardiography has been used to evaluate the presence of late potentials as a marker for sudden cardiac death. We examined prospectively the effects of ACE inhibitor therapy on signal-averaged ECGs and ventricular arrhythmia frequency in 20 patients with moderate to severe left ventricular dysfunction and symptomatic congestive heart failure. METHODS: A signal-averaged ECG and 24 h Holter monitor were performed immediately before and both 1 week and 6 weeks after captopril initiation. The mean dose of captopril at 6 weeks was 38 +/- 31 mg. The patients (19 men and one woman, mean age 63 +/- 12 years) had a baseline ejection fraction of 22 +/- 7% and mean functional class of 2.6 +/- 0.5. The cause of congestive heart failure was coronary artery disease in 18 patients, idiopathic cardiomyopathy in one, and valvular disease in one. RESULTS: All three signal-averaged ECG time-domain parameters tended to improve over the course of the study (study 1, 2, 3: QRS duration (ms) = 108 +/- 11, 106 +/- 12, 105 +/- 11; low-amplitude signal duration (ms) = 30 +/- 8, 31 +/- 10, 28 +/- 10; root mean voltage (microV) = 33 +/- 20, 37 +/- 24, 40 +/- 2, respectively). These changes were not statistically significant, although the improvement in QRS duration was nearly so with P = 0.06. The occurrence and complexity of ventricular ectopy did not appear to be consistently altered. CONCLUSION: ACE inhibitor therapy with captopril did not appear to alter ventricular ectopy over the course of this study. However, the trends toward improvement of signal-averaged ECG parameters deserve further evaluation in a larger and longer-term study.

Action Potentials↗
PubMed1992

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 segment's 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.

Aged↗
PubMed1992

Comparison of percutaneous transluminal coronary angioplasty versus coronary artery bypass grafting for multivessel coronary artery disease.

Percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) are both widely performed in the treatment of multivessel coronary artery disease. Little data directly compare the outcomes of patients treated with these 2 techniques. We examined the characteristics and outcomes of 152 patients who underwent multivessel PTCA and 134 patients who had multivessel CABG. Patients who had prior PTCA or CABG were excluded. Baseline characteristics such as age, sex, and prior myocardial infarction were similar in the 2 groups. Ejection fraction was significantly lower in the CABG group (48 +/- 14%) versus the PTCA patients (53 +/- 15%) (p = 0.002). Narrowing distribution when analyzed by major vascular beds (left anterior descending, circumflex and right coronary arteries) as well as by individual arteries was not significantly different between the groups when left main stenosis was excluded. The surgical group received a larger number of bypasses per patient (3.9) when compared with narrowings dilated in the angioplasty group (3.7) (p less than 0.001). The left internal mammary artery was used in 75% of patients as one of the grafts. Angioplasty success was 95% by standard criteria. Over a mean follow-up of 110 weeks for PTCA patients and 134 weeks for CABG patients the occurrence of death was similar (10 and 14%, respectively) as was myocardial infarction (4 and 2%, respectively). However, all other cardiac events including subsequent cardiac catheterization (49 vs 10%), PTCA (30 vs 2%) and CABG (23 vs 2%) occurred significantly more often in the PTCA group (all p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Direct angioplasty versus initial thrombolytic therapy for acute myocardial infarction: long-term follow-up and changes in practice pattern.

We retrospectively studied the outcomes of patients with acute myocardial infarction who were treated with either direct angioplasty or thrombolytics followed by angioplasty. Two patient cohorts were analyzed: a previously reported (in regard to short-term follow-up) group of 371 patients who now have long-term follow-up (mean, 3.4 years) of survival and event-free survival and a second group of 202 patients who have been treated since publication of our initial data. Both 1-year and 2-year survival were significantly better (p = 0.01 and 0.02, respectively) in the group that was treated with thrombolytics first. Event-free survival (i.e., no myocardial infarction, coronary artery bypass graft surgery, repeat angioplasty) was better overall (p < 0.01) for the group that was treated with thrombolytics first. The more recently treated group of patients also showed benefit in regard to both survival (p = 0.002) and event-free survival (p < 0.01) over a short-term follow-up period (mean, 39 weeks) for patients who were treated initially with thrombolytics as compared with those who were treated with direct angioplasty. Although the initial cohort was very similar to the treatment groups except for age (mean age for the direct angioplasty group was 62 +/- 12 years vs 57 +/- 11 years for thrombolytics first group, (p = 0.0002), several differences existed in the more recent treatment groups. The patients who were more recently treated with direct angioplasty were older, had lower mean ejection fraction, had more extensive coronary artery disease, and were more likely to have had prior coronary artery bypass grafting.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Hypotension during dobutamine stress echocardiography: initial description and clinical relevance.

Hypotension during exercise treadmill testing is correlated with the presence of coronary artery disease, its severity, and prognosis. The importance of hypotension during dobutamine stress testing has not been previously reported to our knowledge. We reviewed 43 cases of hypotension occurring in 42 patients out of a total of 116 consecutive stress dobutamine echocardiographic procedures performed in a total of 112 patients. Of the 42 patients with hypotension, 20 underwent cardiac catheterization. Regional wall motion abnormalities induced by dobutamine infusion were found in 13 of these patients, all of whom had significant (greater than or equal to 70% diameter reduction) coronary artery disease. The remaining seven patients without regional wall motion abnormalities did not have significant coronary artery disease at catheterization. Of the remaining 22 patients with dobutamine-induced hypotension, 20 had no induced regional wall motion abnormalities, were not catheterized, and were followed clinically. None of these patients had a cardiac event during a mean follow-up period of 11.5 months. We conclude that hypotension during dobutamine stress echocardiography in the absence of regional wall motion abnormalities does not indicate significant coronary artery disease or portend an adverse prognosis.

Aged↗