A collaborative project in Connecticut to improve the care of patients with acute myocardial infarction.

BACKGROUND: State-based peer review organizations (PROs) and individual hospitals are challenged to achieve their quality improvement (QI) goals with shrinking resources. In 1993-1994 the Connecticut PRO and 15 local hospitals generated a comparative QI database on acute myocardial infarction (AMI) care for 1,202 Medicare and non-Medicare patients discharged in 1992 and 1993. METHODS: A steering committee composed of hospital and PRO representatives was assembled to provide oversight. PRO staff developed a chart abstraction tool and trained hospital abstracters who collected and submitted data to the PRO for comparative analyses. Written feedback was provided to all hospitals and supplemented with onsite presentations when requested. Each hospital prepared a written QI plan based on its unique data profile. RESULTS: Opportunities for improvement were identified at all hospitals. The most commonly targeted areas for improvement included the use of thrombolytics at presentation, aspirin at presentation and at discharge, and beta blockers at discharge. Improvement interventions included staff education sessions, development of AMI critical paths and standing orders, and storage of appropriate medications in emergency departments. Self-report data from the hospitals indicate improvements in care. DISCUSSION: PROs and hospitals can augment their individual QI activities by working together to share data, resources, and lessons learned. Twenty-three hospitals are now collaborating with the Connecticut PRO on a similarly designed QI project aimed at improving the care of patients hospitalized with atrial fibrillation. This project includes a more formal means of communicating QI interventions.

A collaborative project in Connecticut to improve the care of patients with acute myocardial infarction.

BACKGROUND: State-based peer review organizations (PROs) and individual hospitals are challenged to achieve their quality improvement (QI) goals with shrinking resources. In 1993-1994 the Connecticut PRO and 15 local hospitals generated a comparative QI database on acute myocardial infarction (AMI) care for 1,202 Medicare and non-Medicare patients discharged in 1992 and 1993. METHODS: A steering committee composed of hospital and PRO representatives was assembled to provide oversight. PRO staff developed a chart abstraction tool and trained hospital abstractors who collected and submitted data to the PRO for comparative analyses. Written feedback was provided to all hospitals and supplemented with onsite presentations when requested. Each hospital prepared a written QI plan based on its unique data profile. RESULTS: Opportunities for improvement were identified at all hospitals. The most commonly targeted areas for improvement included the use of thrombolytics at presentation, aspirin at presentation and at discharge, and beta blockers at discharge. Improvement interventions included staff education sessions, development of AMI critical paths and standing orders, and storage of appropriate medications in emergency departments. Self-report data from the hospitals indicate improvements in care. DISCUSSION: PROs and hospitals can augment their individual QI activities by working together to share data, resources, and lessons learned. Twenty-three hospitals are now collaborating with the Connecticut PRO on a similarly designed QI project aimed at improving the care of patients hospitalized with atrial fibrillation. This project includes a more formal means of communicating QI interventions.

Bypass Angioplasty Revascularization Investigation: patient screening, selection, and recruitment.

Percutaneous transluminal coronary angioplasty (PTCA) is currently performed in many patients seeking care because of severe manifestations of multivessel coronary artery disease. Previously, the majority of such patients would have undergone coronary artery bypass grafting (CABG). No definitive evidence is available as to which initial revascularization strategy has the best long-term clinical and economic outcomes. The Bypass Angioplasty Revascularization Investigation (BARI) is the largest of several recent clinical trials that were designed to test the hypothesis that an initial strategy of PTCA in selected patients with multivessel coronary artery disease does not compromise long-term clinical outcome compared with an initial strategy of CABG. This report describes how patients were screened, selected, and recruited in BARI and how this process may influence the results and the interpretation of the trial. During the enrollment period, 25,200 patients undergoing diagnostic coronary angiography at the participating institutions or with off-site angiograms referred to BARI investigators were screened for BARI eligibility. Excluded from screening were patients without coronary artery disease, those with single-vessel disease, prior revascularization, primary congenital, valvular, or myocardial disease, and age > 80 years. Slightly more than half of the patients screened (12,670) were not clinically eligible for BARI because of left main disease, insufficient symptoms, emergency revascularization, or other logistic reasons. Thus, 12,530 patients had severe angina and/or ischemia and were clinically eligible for BARI. Nearly 33% of them (4,110) had multivessel disease, which was suitable for both PTCA and CABG.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of angiotensin-converting enzyme inhibition and AT1 receptor blockade on cardiac pump performance after myocardial infarction in rats.

To determine whether cardiac unloading by inhibition of angiotensin I (AI) to AII conversion by captopril or blockade of the AII receptor (AT1) by losartan was more effective in prevention of the detrimental hemodynamic consequences of myocardial infarction (MI), inhibition of metabolic production of AII by captopril was compared with blockade of AT1 with losartan in Sprague-Dawley rats with large MI. Infarcts were created by surgical occlusion of the left main coronary artery and oral drug therapy initiated immediately and continued until hemodynamic evaluation seven days later. Heart weight was unchanged in untreated infarcted animals, whereas captopril reduced heart weight in control animals and losartan increased heart weight in infarcted animals. Left ventricular (LV) peak systolic blood pressure (SBP) was lower in treated and untreated infarcted animals. Although captopril reduced end-diastolic pressure (EDP) to a greater degree than losartan, all infarcted group showed an increase in this parameter with respect to similarly treated controls. LV peak rates of pressure increase and decay in infarcted hearts were decreased significantly more by captopril than by losartan administration. Captopril also impaired right side cardiac function more than losartan when peak rate of pressure increase was evaluated. Thus, inhibition of the effects of AII during cardiac failure improved but did not normalize cardiac pump performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of hypertension and coronary constriction on cardiac function, morphology, and contractile proteins in rats.

In an attempt to elucidate the effects of two major risk factors of heart failure in humans, high blood pressure and coronary artery disease, renal hypertension and coronary artery constriction were induced singularly and in combination in rats, and the functional, structural, and biochemical alterations of the myocardium were examined 12-13 wk later. Renal hypertension (RH), coronary narrowing (CN), and their association (NH) resulted in left ventricular failure demonstrated by a significant increase in left ventricular end-diastolic pressure, a decrease in +dP/dt and -dP/dt, and a reduction in stroke volume and cardiac output. Measurements of ventricular loading documented that RH was characterized by elevations in systolic and diastolic wall stress of 42 and 160%, respectively. Corresponding changes with NH were 80 and 315%. CN was accompanied by an augmentation of diastolic wall stress only (280%). The abnormalities in mural stress were coupled with reductions in systolic and diastolic wall thickness-to-chamber radius ratios of 39 and 29% after CN. These anatomic parameters were preserved with RH, whereas the systolic wall thickness-to-chamber radius ratio was reduced 31% with NH. Structurally, multiple foci of replacement fibrosis were found with each intervention. The sites of tissue injury and their volume percent in the myocardium were comparable with CN and RH but were significantly more numerous and occupied a larger fraction of the ventricular wall in the presence of NH. Biochemically, the calcium dose-response curve of myofibrillar Mg2+ adenosinetriphosphatase (ATPase) activity did not vary with CN, RH, and NH. In contrast, a marked decrease in Ca2+ myosin ATPase activity was found in NH rats in association with a shift in myosin isoenzymes from V1 to V3. In conclusion, multiple physiological, morphological, and biochemical factors may participate in the generation of the abnormalities in ventricular loading with hypertension and/or coronary artery stenosis.

Myocardial infarction, cardiac anatomy and ventricular loading.

To see whether the hypertrophic response of the surviving myocardium after infarction leads to a complete reconstitution of ventricular mass, the left coronary artery was ligated in rats and the animals killed one month later. In infarcts affecting an average of 38% of the free wall of the left ventricle, the ratio of wall thickness to chamber radius remained essentially constant. On the other hand, the ratio decreased significantly in the presence of infarcts involving an average of 60% of the ventricular wall. In addition, inadequate growth adaptations were detected in both groups of infarcts with respect to myocyte volume and length and to capillary volume and length. These defects in the regeneration of myocardial structures were associated with elevations in diastolic wall stress which were more prominent in the larger infarct group. The limited growth reaction of the myocyte and vascular compartments may be implicated in the persistence of cardiac dysfunction and failure late after infarction.

Left main coronary artery aneurysm following percutaneous transluminal angioplasty: a report of a case and review of the literature.

Since its introduction in 1977, the number of PTCAs and its indications have grown. Along with more frequent usage, newer complications have been reported. Aneurysm of left main coronary artery is rare. This report describes the formation of a new non-obstructing aneurysm in the left main coronary artery after PTCA of left circumflex artery. The patient has had 7 yr of follow-up with a benign clinical course.

Origin of all three coronary arteries from separate ostia in the right sinus of Valsalva: a rarely reported coronary artery anomaly.

Anomalous origin of the circumflex and left anterior descending coronary arteries from separate ostia in the right sinus of Valsalva is a rarely reported phenomenon. Few clinical details concerning patients with this anomaly are available in the literature. Angiographic and clinical data in an adult patient with this finding are reported here.

Variability of electrocardiographic precordial lead placement: a method to improve accuracy and reliability.

Variability in precordial lead placement is a recognized source of electrocardiographic inaccuracy and lack of reproducibility. In an attempt to reduce error, we evaluated a new device to facilitate and guide precordial lead placement. This study involved three phases: (1) comparison of device-guided electrocardiogram with ECGs obtained by deliberate misplacement of precordial leads on the same patient; (2) electrocardiograms obtained by using the precordial lead device versus those obtained by standard technician methods; (3) reproducibility of precordial electrocardiographic leads between two technicians using the device to guide lead placement. Deliberate misplacement of precordial leads by 2 cm resulted in significant electrocardiographic interpretation changes in all patients. Comparing electrocardiograms obtained after device-guided precordial placement with those obtained after technician placement resulted in variations in 60% of patients including changes in R-wave amplitude, ST segments, Q waves, and transition zone. Significant Q-wave appearance/disappearance and/or significant ST-segment elevation/depression occurred in 19% of patients in Phase II. Sixteen percent of electrocardiograms showed significant changes when analyzed by an experienced electrocardiographer and 10% when interpreted by computer. Variable lead placements and resulting electrocardiographic alterations were not seen by either of two technicians when the device was used. This study confirms the widespread variability in precordial electrocardiograms secondary to lead misplacement. The use of a device to assist in the placement of precordial leads ensures accuracy and reproducibility of electrocardiography. Improved precision and quality control in this laboratory test have important implications in health care and its costs.

Atrial-septal-aneurysm-associated thrombus and stroke: Demonstration with transesophageal echocardiography.

Atrial septal aneurysm is an increasingly recognized cardiac abnormality. It represents a marked bulging of the interatrial septum into one atrium or the other. A consistent association between this structure and embolic stroke has been demonstrated. Because of the high prevalence of patent foramen ovale or atrial septal defect associated with this structure, paradoxical embolism has been suggested as a mechanism for embolic events. An alternate explanation is the local association of the aneurysm with thrombus. Few data have been found to support this mechanism, however. We report a young woman with multiple strokes during pregnancy in whom transesophageal echocardiography allowed the in vivo demonstration of atrial-septal-aneurysm-associated thrombus. This observation lends further support to the "local thrombus" mechanism of embolie events. It also underscores the potential utility of transesophageal echocardiography in evaluating patients with stroke of uncertain etiology.

Thrombolysis in Myocardial Infarction (TIMI) phase II trial: outcome comparison of a "conservative strategy" in community versus tertiary hospitals. The TIMI Research Group.

In the conservative strategy arm of phase II of the Thrombolysis in Myocardial Infarction (TIMI) trial, 1,461 patients were treated with intravenous recombinant tissue-type plasminogen activator (rt-PA). Coronary angiography, with angioplasty if feasible, was to be performed only for recurrent spontaneous or exercise-induced ischemia. In this study results in patients treated by this strategy in community and tertiary hospitals are compared. Despite similar baseline findings in the two groups, coronary angiography was performed within 42 days in more patients (542 [48%] of 1,155) initially admitted to a tertiary hospital (on-site coronary angiography/angioplasty available) than in those (94 [32%] of 306) admitted to a community hospital (transfer to tertiary hospital for coronary angiography/angioplasty) (p less than 0.001). This different approach resulted in a greater use of coronary angioplasty (203 [18%] of 1,155 versus 32 [11%] of 306, p less than 0.01), coronary artery bypass surgery (133 [12%] of 1,155 versus 23 [8%] of 306, p less than 0.05) and blood transfusions (139 [12%] of 1,155 versus 17 [5.5%] of 306, p less than 0.001) in patients admitted to a tertiary than to a community hospital. However, there were no significant differences between the two groups in mortality, recurrent myocardial infarction or left ventricular function. These results demonstrate that a conservative strategy after treatment of acute myocardial infarction with rt-PA is applicable in the community hospital setting.

Identification of calcified intracardiac lesions using gradient echo MR imaging.

Gradient echo signal imaging (GEI) has expanded the clinical role of magnetic resonance (MR) imaging of the heart. The role of GEI to evaluate intracardiac calcified lesions was studied. All patients were imaged with both conventional spin echo (SE) techniques and GEI. The GEI demonstrated that calcific cardiac lesions exhibit magnetic susceptibility differences and produce marked hypointensity throughout the calcified area. All patients had echocardiographic and fluoroscopic evidence of cardiac calcification and surgical confirmation of calcified lesions. The SE MR was unable to define the intracardiac calcification. Gradient echo imaging may be a helpful adjunct in the complete definition of intracardiac calcific lesions. When profound signal void areas are detected on cardiac GEI studies, calcification should be suspected.

MR imaging in the definition of coronary artery anomalies.

Coronary angiography remains the standard imaging technique to study coronary artery anatomy. Coronary artery aneurysms and fistulas are often incompletely visualized with routine angiography. Magnetic resonance (MR) imaging of such coronary anomalies is presented. The MR images improve the preoperative assessment of patients with coronary artery aneurysms and fistulas.

Postoperative evaluation of ascending aortic prosthetic conduits by magnetic resonance imaging.

Operative repair of ascending thoracic aortic dissection and aneurysm often involves the placement of prosthetic aortic conduits and stents with wrapping of the native aorta around the prosthetic device. Postoperative assessment has been clinical because of the absence of an adequate noninvasive imaging modality and a reluctance to perform invasive contrast aortography. Magnetic resonance imaging was performed on ten patients after operative placement of a prosthetic ascending aortic graft. The MR images were reviewed and a grading system was devised based on appearance of the operative site. An increase in MR signal was noted in some patients between the graft and wrapped native vessel. In 20 percent of patients vascular lumen compromise was noted. Magnetic resonance imaging offers a noninvasive technique to assess postoperative complications and offers a viable alternative to invasive contrast aortography.

Electrocardiographic pseudo-myocardial infarct pattern in malignant cardiac disease.

A patient with disseminated diffuse histiocytic lymphoma had persistent electrocardiographic (ECG) signs of acute myocardial infarction without clinical, enzymatic, or hemodynamic evidence of myocardial necrosis. The ECG findings were felt to be secondary to myocardial tumor invasion by antemortem noninvasive testing. This was confirmed by postmortem examination. Based on this report and a literature review, the particular ECG findings noted (lateral leads) are felt to be highly predictive of direct tumor invasion in this setting.