Paul T. Vaitkus

Embolic potential, prevention and management of mural thrombus complicating anterior myocardial infarction: A meta-analysis

OBJECTIVES The management of mural thrombus complicating acute anterior myocardial infarction remains controversial in part because of the small size of studies on this topic. We performed a meta-analysis of published studies to address three questions: 1) What is the embolic risk of mural thrombi after myocardial infarction? 2) What is the impact of systemic anticoagulation in reducing the embolic risk of mural thrombi? 3) What is the impact of systemic anticoagulation, thrombolytic therapy and antiplatelet therapy in preventing mural thrombus formation? METHODS Studies were identified by a computerized and manual search and were included if they were published in manuscript form in the English-language literature. Pooling of data was performed by calculating the Mantel-Haenszel odds ratio and an event rate difference by the method of DerSimonian and Laird. RESULTS The odds ratio for increased risk of emboli in the presence of echocardiographically demonstrated mural thrombus (11 studies, 856 patients) was 5.45 (95% confidence interval [CI] 3.02 to 9.83), and the event rate difference was 0.09 (95% CI 0.03 to 0.14). The odds ratio of anticoagulation versus no anticoagulation in preventing embolization (seven studies, 270 patients) was 0.14 (95% CI 0.04 to 0.52) with an event rate difference of -0.33 (95% CI -0.50 to -0.16). The odds ratio of anticoagulation versus control in preventing mural thrombus formation (four studies, 307 patients) was 0.32 (95% CI 0.20 to 0.52), and the event rate difference was -0.19 (95% CI -0.09 to -0.28). The odds ratio for thrombolytic therapy in preventing mural thrombus (six studies, 390 patients) was 0.48 (95% CI 0.29 to 0.79) with an event rate difference of -0.16 (95% CI 0.10 to -0.42), whereas for antiplatelet agents (two studies, 112 patients) the odds ratio was 1.43 (95% CI 0.04 to 56.8) with an event rate difference of 0.16 (95% CI -0.20 to 0.52). CONCLUSIONS This analysis supports the hypotheses that 1) mural thrombus after myocardial infarction poses a significantly increased risk of embolization, 2) the risk of embolization is reduced by systemic anticoagulation, and 3) anticoagulation can prevent mural thrombus formation. Thrombolytic therapy may prevent mural thrombus formation, but evidence for a similar benefit of antiplatelet therapy is lacking.

The Ability of Vegetation Size on Echocardiography to Predict Clinical Complications: A Meta-analysis

To clarify whether echocardiographic detection of a vegetation 10 mm or larger in size in patients with left-sided infective endocarditis poses an increased risk for complications, we performed a meta-analysis of English-language publications identified by a computerized search of the key words infective endocarditis and echocardiography. A pooled odds ratio was calculated by using the Robins, Greenland, and Breslow estimate of variance. The pooled odds ratio for increased risk of systemic embolization in the presence of a vegetation >10 mm (10 studies, 738 patients) was 2.80 (95% confidence interval [CI] 1.95 to 4.02; p < 0.01). The odds ratio of requiring valve-replacement surgery (seven studies, 549 patients) was 2.95 (95% CI 1.90 to 4.58; p < 0.01). The odds ratio of death (six studies, 476 patients) was 1.55 (95% CI 0.92 to 2.60; p = 0.10). Thus this analysis supports the hypothesis that echocardiographically detected left-sided vegetations >10 mm pose a significantly increased risk of (1) systemic embolization and (2) a need for valve-replacement surgery than cases where either no or smaller vegetations are detected.

Constrictive pericarditis versus restrictive cardiomyopathy: a reappraisal and update of diagnostic criteria.

Distinguishing constrictive pericarditis from restrictive cardiomyopathy is a difficult clinical challenge. We review published reports in which hemodynamic criteria were used to differentiate these two diagnoses. There were 82 cases of constriction and 37 cases of restriction. The overall predictive accuracy of the difference between right and left ventricular end-diastolic pressures (RVEDP and LVEDP), RV systolic pressure, and the ratio of RVEDP to RV systolic pressure were 85%, 70%, and 76%, respectively. If all three criteria were concordant, the probability of having correctly classified the patient was greater than 90%. However, one fourth of patients could not be classified by hemodynamic criteria. There are few data to support the use of hemodynamic measurements after exercise or volume infusion to separate these two groups. Numerous recent studies have reported on the ability of left ventriculography, Doppler echocardiography, or radionuclide angiography to distinguish constriction from restriction. Many of the proposed indices appear promising, but these studies suffer from small sample size, potential selection bias, and complexity of the proposed criteria, which have limited their widespread application. New imaging technologies, such as CT scanning or MRI have been applied in a limited number of cases, but appear to be a sensitive means of detecting abnormal pericardium. Endomyocardial biopsy has proven useful in establishing the diagnosis of infiltrative cardiomyopathies, eliminating in those cases the need for surgical intervention. The finding of myocarditis must be considered a nonspecific finding that does not preclude thoracotomy. Since constrictive pericarditis is a surgically curable condition, the distinction between constrictive and restrictive disease is of critical importance. Taking into account the relative contribution of data derived from hemodynamic, imaging,and biopsy studies, we propose an algorithm for the selection of appropriate candidates for pericardial biopsy and stripping.

Percutaneous transluminal coronary angioplasty in the elderly: Epidemiology, clinical risk factors, and in-hospital outcomes☆☆☆★

Objectives To explore the relation between older age and clinical presentation, procedural success, and in-hospital outcomes among a large unselected population undergoing percutaneous transluminal coronary angioplasty (PTCA). Background Although more elderly patients are receiving PTCA, studies of post-PTCA outcomes among the elderly have been limited by small numbers and exclusive selection criteria. Methods Data were collected as a part of a prospective registry of all percutaneous coronary interventions performed in Maine, New Hampshire, and from 1 institution in Massachusetts between October 1989 and December 1993. Comparisons across 4 age groups, (<60, 60 to 69, 70 to 79, and 80 years and above) were performed using chi-square tests, the Mantel-Haenzsel test for trend, and logistic regression. Results Twelve thousand one hundred seventy-two hospitalizations for PTCA were performed with 507 of them (4%) in persons at least 80 years old. Octogenarians were more likely to be women, have multivessel disease, high-grade stenoses, and complex lesions but were less likely to have hypercholesterolemia, a history of smoking, or have undergone a previous PTCA. In the elderly, PTCAs were more often performed urgently and for unstable syndromes compared with younger age groups. Advancing age is strongly associated with in-hospital death, and among the oldest old with an increased risk of postprocedural myocardial infarction. Despite differing presentation and procedural priority, angiographic success and subsequent bypass surgery did not vary by age. Conclusions With the increasing age of the population at large as well as that segment at risk for cardiac revascularization, information about age-associated risks of the procedure, especially the substantially higher risk of death in octogenarians, will be critical for both physicians and patients considering PTCA. (Am Heart J 1999;137:639-45.)

Cause of in-hospital death in 12,232 consecutive patients undergoing percutaneous transluminal coronary angioplasty ☆ ☆☆

BACKGROUND Some deaths after percutaneous coronary angioplasty (PTCA) occur in high-risk situations (eg, shock), whereas others are unexpected and related to procedural complications. To better describe the epidemiologic causes of death after PTCA, we undertook a systematic review of all in-hospital PTCA deaths in Northern New England from 1990 to 1993. METHODS The medical records of 121 patients who died during their acute hospitalization for PTCA were reviewed with a standardized data extraction tool to determine a mode of death (eg, low output failure, arrhythmia, respiratory failure) and a circumstance of death (eg, death attributable to a procedural complication, preexisting acute cardiac disease). Any death not classified as a procedural complication was reviewed by a committee and the circumstance of death assigned by a majority rule. RESULTS Low-output failure was the most common mode of death occurring in 80 (66.1%) of 121 patients. Other modes of death included ventricular arrhythmias (10.7%), stroke (4.1%), preexisting renal failure (4.1%), bleeding (2.5%), ventricular rupture (2.5%), respiratory failure (2.5%), pulmonary embolism (1.7%), and infection (1.7%). The circumstance of death was a procedural complication in 65 patients (53.7%) and a preexisting acute cardiac condition in 41 patients (33.9%). Women were more likely to die of a procedural complication than were men. CONCLUSION Procedural complications account for half of all post-PTCA deaths and are a particular problem for women. Other deaths are more directly related to patient acuity or noncardiac, comorbid conditions. Understanding why women face an increased risk of procedural complications may lead to improved outcomes for all patients.

The Relationship between the Supply of Cardiac Catheterization Laboratories, Cardiologists and the use of Invasive Cardiac Procedures in Northern New England

Objectives: Utilization rates of coronary angiography and cardiac revascularization have been found to vary between areas. This study addresses the relationship between resource supply and procedure rates. Methods: We compared the association of per capita catheterization laboratories, per capita cardiologists and multi-provider markets (where more than one hospital offers coronary angiography services) with the utilization rates for angiography and cardiac revascularization in northern New England, USA. Administrative data were used to capture invasive cardiac procedures. Small area analyses were used to create coronary angiography service areas. Linear regression methods were used to measure associations between the resource supply and utilization rates. Results: Variation in the use of invasive cardiac procedures was strongly associated with the population-based availability of catheterization facilities and multi-provider markets and unrelated to cardiologist supply or need (as reflected in the hospitalization rates for myocardial infarction). In the multivariate model, an increase of 1 catheterization laboratory per 100 000 population was associated with an increase in the angiography rate of 1.62 per 1000 population; those service areas with multi-provider markets were associated with an additional increase in the angiography rate of 1.27 per 1000 population (R 2= 0.84, P = 0.0006). There was a moderately strong relationship between the catheterization laboratories per capita and the revascularization rates (R 2 = 0.43, P = 0.029). Angiography rates were highly associated with cardiac revascularization rates: An increase in the angiography rate of 1 per 1000 population was associated with a 0.46 per 1000 increase in the cardiac revascularization rate (R 2 = 0.85, P = 0.0001). Conclusions: Our work suggests that current efforts to address variation in cardiac procedures through activities such as appropriateness criteria, guidelines and utilization review are misdirected and should be redirected towards capacity, in this case the supply of catheterization facilities.

Management and immediate outcome of patients with intracoronary thrombus during percutaneous transluminal coronary angioplasty

A retrospective analysis of our experience with intraprocedural thrombus complicating percutaneous transluminal coronary angioplasty (PTCA) was undertaken. Of 983 PTCA procedures reviewed, 62 (6.3%) were complicated by thrombus. Patients were managed conservatively (group I, n = 18), with redilation (group II, n = 17), or with intracoronary urokinase and redilation (group III, n = 27). The three groups did not differ with respect to demographic or baseline angiographic variables, but complications, defined as death, myocardial infarction, bypass surgery, or threatened occlusion requiring emergency stenting, occurred in 11% of patients in group I, 24% in group II, and 48% in group III. Occlusive thrombus behavior was observed in 80% of these 62 patients. Patients with complications were less likely to have received antecedent antiplatelet therapy (79% vs 95% of patients without complications), had more complex baseline lesion morphology, more often had thrombus present at baseline (42% vs 19%), and more often had a low activated clotting time at the start of PTCA (53% vs 8%). Thrombi that led to complications more frequently exhibited occlusive behavior before therapy was begun (95% vs 71%) and more often occurred in the setting of intimal dissection (42% vs 14%). Patients undergoing PTCA at the time of diagnostic catheterization were more likely to have complications than those in whom PTCA was delayed. A successful outcome was more likely (83% vs 27%, p = 0.03) in group III if at least 140,000 U of urokinase were administered within 50 minutes of the appearance of thrombus. Thus intracoronary thrombus formation during PTCA remains a significant source of morbidity.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in electrophysiological substrate in patients with coronary artery disease and cardiac arrest or ventricular tachycardia. Insights from endocardial mapping and signal-averaged electrocardiography.

BackgroundMany studies have combined patients with hemodynamically well-tolerated ventricular tachycardia (VT) and those with cardiac arrest (CA) as a single, homogenous group. Recent studies suggest that these two groups have different electrophysiological substrates and responses to therapy. Most of these studies, however, enrolled patientswith a variety of cardiac diagnoses. Methods and ResultsWe used signal-averaged electrocardiography (SAECG) and endocardial catheter mapping to define the electrophysiological substrate in patients with coronary artery disease and VT or CA and correlate the results of the two methods. We also examined the usefulness of SAECG in CA patients to differentiate those with inducible arrhythmias from those who are noninducible. VT patients were more likely to have had a prior myocardial infarction (p =0.0005) and to have inducible arrhythmias (p =0.0001) than were CA patients. The induced arrhythmias in patients who presented with VT was VT in more than 90% of cases, whereas in CA patients, polymorphic ventricular tachycardia (PMVT) accounted for one third of induced arrhythmias. Mean filtered QRS duration was longer (135 versus 120 msec) and the terminal QRS voltage was smaller (20 versus 34, V) in VT than in CA patients (p < 0.01). Sixty-three percent of CA patients and 87% of VT patients had abnormal SAECG (p =0.001). VT patients had more extensive endocardial abnormalities and more abnormal (53% versus 40%, p = 0.002), fractionated (8% versus 3%o, p=0.02), late (17% versus 8%, p=0.0003), and late abnormal or fractionated (14% versus 4%, p=0.0001) sites than CA patients. VT patients had a greater duration of the longest electrogram (129 versus 109 msec, p = 0.0006) and total endocardial activation time (68 versus 54 msec, p = 0.009). Among CA patients, those with induced VT had more extensive substrate than did those with induced PMVT and were similar to VT patients with induced VT. Among CA patients, the trend for more patients with inducible VT (77%) or PMVT (55%) than noninducible patients (47%) to have an abnormal SAECG did not reach statistical significance (p =0.14). The positive and negative predictive values of an abnormal SAECG were 77%O and 44%, respectively. ConclusionsVT patients have more extensive endocardial substrate than CA patients, which translates into greater and more frequent SAECG abnormalities. Among CA patients, there are significant differences in substrate between patients with induced VT and those with induced PMVT. SAECG is not useful in differentiating CA patients who have inducible VT or PMVT from those who do not.

Cost Advantages of an Ad Hoc Angioplasty Strategy

OBJECTIVES We sought to determine the cost advantage of a strategy of same-sitting diagnostic catheterization and percutaneous transluminal coronary angioplasty (PTCA) (ad hoc) in comparison with staged PTCA. BACKGROUND It is widely assumed that an ad hoc strategy lowers costs by reducing the length of hospital stay (LOS). However, this assumption has not been examined in a contemporary data set. METHODS We studied 395 patients undergoing PTCA during 6 consecutive months. Cost analysis was performed using standard cost-accounting methods and a mature cost-accounting system. Costs were examined within three clinical strata based on the indication for PTCA (stable angina, unstable angina and after myocardial infarction [MI]). RESULTS For the entire patient cohort, there was no significant cost advantage of an ad hoc approach within any of the strata, although there was a nonsignificant trend toward an ad hoc approach in patients with stable angina. For patients treated with conventional balloon PTCA alone, the lack of a significant difference between ad hoc and staged strategies persisted. For patients who received stents, there was a significant cost advantage of an ad hoc approach in all three clinical strata. An important cost driver was the occurrence of complications. Differences in the rates of complications did not reach statistical significance between ad hoc and staged strategies, but even a small trend toward greater complications in patients who had the ad hoc strategy negated cost and LOS advantages. Our study had the power to detect significant cost differences of

Ischemia-induced changes in human endocardial electrograms during percutaneous transluminal coronary angioplasty

1,300 for patients with stable angina,