The Connecticut Cardiovascular Consortium: a unique, state-wide research collaboration to advance clinical outcomes in patients with heart disease.

The establishment of "best clinical practices" founded upon evidence-based medicine has become an increasingly important priority. Frequently, management guidelines are derived from published research data and disseminated among practitioners to help optimize patient care. The ultimate clinical impact of these guidelines in the "real world," however, is often clouded by an incomplete assessment of patient outcomes throughout the continuum of health-care delivery models. In order to address this gap in clinical outcome assessment, we propose to establish the Connecticut Cardiovascular Consortium. The Consortium will consist of a collaborative partnership among all 31 Connecticut hospitals working in concert with Connecticut Office of Health Care Access (OHCA). The primary objective of the Consortium will be to assess, compare, and optimize clinical outcomes among Connecticut residents with cardiovascular disease. As an initial goal for the Consortium, we further propose to undertake a prospective, observational study of Connecticut residents who present with ST Segment Elevation Acute Myocardial Infarction (STEMI). Recent advances in pharmacologic and mechanical reperfusion for STEMI have resulted in a need to define the optimal use of these therapies in the community at large. The primary purpose of this study will be to determine the relative merits of different treatment patterns for STEMI with regard to the use of fibrinolytic therapy and percutaneous coronary intervention (PCI). Particular emphasis will be placed on assessing the relative benefits of urgent mechanical revascularization performed at the state's seven tertiary facilities with PCI capability compared to all other treatment modalities. Successful completion of this unique collaborative endeavor is expected to have significant impact on improved patient care and on current health-care policy for medical resource allocation. Moreover, continued collaboration of health-care providers within the Connecticut Cardiovascular Consortium infrastructure should serve as a useful mechanism for ongoing improvements in evidence-based cardiovascular medicine and clinical research in the state of Connecticut.

Local intramural heparin delivery during primary angioplasty for acute myocardial infarction: results of the Local PAMI Pilot Study.

The feasibility and safety of local heparin delivery during acute infarct angioplasty was evaluated in a prospective, multicenter, 120-patient series. Angioplasty was performed using standard techniques, after which heparin (4,000 U) was delivered locally; 25% of patients received stents. Procedural success was reported in 98% of patients; 6.7% of patients suffered death, reinfarction, recurrent ischemia, or stroke during the index hospitalization. The 6-month target vessel revascularization rate was 12.5%. Local heparin therapy with provisional stenting in acute myocardial infarction patients is safe, feasible, associated with a low rate of infarct artery revascularization at 6 months, and may potentially eliminate the need for systemic heparin following the procedure.

Improved clinical effectiveness with a collagen vascular hemostasis device for shortened immobilization time following diagnostic angiography and percutaneous transluminal coronary angioplasty.

This study prospectively compared immobilization time followed by use of a vascular hemostasis device (VasoSeal) versus manual compression to achieve hemostasis at the arterial puncture after angiography and percutaneous transluminal coronary angioplasty (PTCA). The trial shows that use of a vascular hemostasis device results in earlier mobilization, even in highly anticoagulated PTCA patients compared with manual compression, with no statistically significant complications.

Prospective evaluation of viable myocardium by quantitative dipyridamole-thallium-201 scintigraphy and radionuclide ventriculography.

Improvement of myocardial function is a major goal of coronary revascularization. Considerable interest remains in the preoperative identification of viable myocardium. We examined 26 consecutive patients with left ventricular dysfunction undergoing coronary artery bypass grafting. Serial dipyridamole-thallium imaging and radionuclide ventriculography was performed preoperatively and postoperatively. The relationship between preoperative and postoperative thallium perfusion and segmental wall motion was analyzed. The mean preoperative ejection fraction was 32 +/- 9 (21 to 51%) and increased to 41 +/- 12 (17 to 67%) postoperatively (p > 0.01). Seventy-seven percent of patients improved their global ejection fraction postoperatively by > 5%. Thallium perfusion improved postoperatively in 84% of reversible defects vs 63% of partially reversible defects and 35% of fixed defects. Segments with either reversible or partially reversible thallium defects showed an improved postoperative wall motion in 71% and 68%, respectively. Postoperative wall motion improved in 43% of fixed defects. Overall, 67% of hypokinetic segments showed improved postoperative wall motion while only 29% of akinetic or dyskinetic segments improved postoperatively. Preoperative thallium redistribution coupled with preserved wall motion was predictive of improvement in wall motion was predictive of improvement in wall motion postoperatively and indirectly indicates myocardial viability. However, 43% of fixed defects also showed improved postoperative wall motion. A significant improvement in global ejection fraction was found and could be predicted by a linear regression analysis utilizing clinical and thallium parameters.

A multicenter randomized trial comparing a percutaneous collagen hemostasis device with conventional manual compression after diagnostic angiography and angioplasty.

OBJECTIVES: A new percutaneous collagen hemostasis device was compared with conventional compression techniques after diagnostic catheterization and angioplasty. BACKGROUND: Peripheral vascular complications after diagnostic catheterization or more complex interventional procedures, as well as the discomfort of manual compression and prolonged bed rest, represent significant morbidity for invasive cardiac procedures. METHODS: A prospective, multicenter, randomized trial was designed to compare the hemostasis time in minutes and the incidence of vascular complications in patients receiving a vascular hemostasis device with those undergoing conventional compression techniques. RESULTS: After diagnostic catheterization, hemostasis time was significantly less with the vascular hemostasis device than with conventional manual compression (4.1 +/- 2.8 min [n = 90 patients] vs. 17.6 +/- 9.2 min [n = 75], p < 0.0001). This difference was greater in patients undergoing angioplasty and was unrelated to the anticoagulation status (4.3 +/- 3.7 min [n = 71 not receiving heparin], 7.6 +/- 11.6 min [n = 85 receiving heparin], 33.6 +/- 24.2 min [n = 134 control patients not receiving heparin], p < 0.0001 vs. control patients). The time from the start of the procedure to ambulation was slightly less after diagnostic catheterization in patients treated with the device (13.3 +/- 12.1 h vs. 19.2 +/- 17.8 h, p < 0.05). It was also less in patients who underwent angioplasty when the device was used after discontinuation of anticoagulation (23.0 +/- 11.1 h, without heparin), as compared with control compression techniques (32.7 +/- 18.8 h, p < 0.0001). Time to ambulation was even shorter (16.1 +/- 11.1 h, p < 0.0001) in patients in whom the device was placed immediately after angioplasty while they were still fully anticoagulated with a prolonged activated clotting time (336 +/- 85 s). There were no major complications (surgery or transfusion) after diagnostic catheterization and a low incidence of major complications in patients who underwent angioplasty (0.7% in control patients, 1.4% with the device without heparin, 1.2% with the device and heparin, p = NS). After angioplasty, there was a trend toward fewer hematomas when the device was used in the absence of heparin (4.2% vs. 9.7% in control patients, p = 0.14). CONCLUSIONS: A new vascular hemostasis device can significantly reduce the puncture site hemostasis time and the time to ambulation without significantly increasing the risk of peripheral vascular complications. The role of this technology in reducing complications, length of hospital stay and cost remains to be determined.

Predictive value of quantitative dipyridamole-thallium scintigraphy in assessing cardiovascular risk after vascular surgery in diabetes mellitus.

Cardiac complications represent a major risk to patients undergoing vascular surgery. Diabetic patients may be particularly prone to such complications due to the high incidence of concomitant coronary artery disease, the severity of which may be clinically unrecognized. Attempts to stratify groups by clinical criteria have been useful but lack the predictive value of currently used noninvasive techniques such as dipyridamole-thallium scintigraphy. One hundred one diabetic patients were evaluated with dipyridamole-thallium scintigraphy before undergoing vascular surgery. The incidence of thallium abnormalities was high (80%) and did not correlate with clinical markers of coronary disease. Even in a subgroup of patients with no overt clinical evidence of underlying heart disease, thallium abnormalities were present in 59%. Cardiovascular complications, however, occurred in only 11% of all patients. Statistically significant prediction of risk was not achieved with simple assessment of thallium results as normal or abnormal. Quantification of total number of reversible defects, as well as assessment of ischemia in the distribution of the left anterior descending coronary artery was required for optimum predictive accuracy. The prevalence of dipyridamole-thallium abnormalities in a diabetic population is much higher than that reported in nondiabetic patients and cannot be predicted by usual clinical indicators of heart disease. In addition, cardiovascular risk of vascular surgery can be optimally assessed by quantitative analysis of dipyridamole-thallium scintigraphy and identification of high- and low-risk subgroups.

Usefulness of dipyridamole-thallium-201 perfusion scanning for distinguishing ischemic from nonischemic cardiomyopathy.

To determine noninvasively the etiology of left ventricular (LV) dysfunction, 22 patients with a diagnosis of cardiomyopathy determined via cardiac catheterization and 5 normal control subjects underwent radionuclide ventriculography and intravenous dipyridamole-thallium-201 perfusion scanning. Both ischemically and nonischemically induced LV dysfunction had comparable global LV ejection fractions (24 +/- 6 vs 23 +/- 8%, respectively) and extent of segmental wall motion abnormalities. Right ventricular ejection fraction was significantly better in the group with an ischemic etiology of LV dysfunction (41 +/- 26 vs 13 +/- 10%, p less than 0.005) but significant group overlap was present. However, computer-assisted analysis of dipyridamole-thallium-201 myocardial perfusion scanning demonstrated more homogeneous myocardial perfusion in idiopathic cardiomyopathy (mean perfusion defect 25 +/- 11 vs 6 +/- 6%, p less than 0.001) and successfully predicted the correct etiology of LV dysfunction in 20 of 22 (91%) patients.

Magnitude and determinants of coronary artery disease in juvenile-onset, insulin-dependent diabetes mellitus.

The risk of premature coronary artery disease (CAD) and its determinants were investigated in a cohort of 292 patients with juvenile-onset, insulin-dependent diabetes mellitus (IDDM) who were followed for 20 to 40 years. Although patients with juvenile-onset IDDM had an extremely high risk of premature CAD, the earliest deaths due to CAD did not occur until late in the third decade of life. After age 30 years, the mortality rate due to CAD increased rapidly, equally in men and women, and particularly among persons with renal complications. By age 55 years the cumulative mortality rate due to CAD was 35 +/- 5%. This was far higher than the corresponding rate for nondiabetic persons in the Framingham Heart Study, 8% for men and 4% for women. Angina and acute nonfatal myocardial infarction followed a similar pattern, as did asymptomatic CAD detected by stress test, so that their combined prevalence rate was 33% among survivors aged 45 to 59 years. Age at onset of IDDM and the presence of eye complications did not contribute to risk of premature CAD. This pattern suggests that juvenile-onset diabetes and its renal complications are modifiers of the natural history of atherosclerosis in that although they profoundly accelerate progression of early atherosclerotic lesions to very severe CAD, they may not contribute to initiation of atherosclerosis.

Hemodynamic effects of intravenous amiodarone.

Amiodarone is a potent antiarrhythmic agent that is effective in controlling both atrial and ventricular arrhythmias. Recently, intravenous administration was demonstrated to be effective in the acute management of rhythm disorders and, in addition, appeared to shorten the loading period normally required for oral drug administration. This investigation examined the hemodynamic effects of amiodarone after both acute intravenous bolus and continuous intravenous administration. Patients with a left ventricular ejection fraction greater than 0.35 experienced improved cardiac performance due to both acute and chronic peripheral vasodilation. However, patients with a lower ejection fraction developed a 20% decrease in cardiac index and clinically significant elevation of right heart pressures after acute bolus administration; these changes were variably compensated for by peripheral vasodilation when the drug was administered intravenously over 3 to 5 days continuously. Therefore, intravenous amiodarone can result in significant impairment of left ventricular performance in patients with preexisting left ventricular dysfunction.

The role of coronary adrenergic receptors in the response to nitroglycerine and the regulation of large and small vessel resistance.

The role of coronary adrenergic receptors in response to nitroglycerine and in the regulation of large and small coronary vascular resistance was evaluated in two separate studies involving fifteen anesthetized mongrel dog preparations, before and after alpha- and beta-adrenergic blockade, respectively. Coronary blood flow (CBF) was measured through the left anterior descending (LAD) coronary artery by a non-cannulating electromagnetic flow probe. Pressure catheters were inserted into the arch of the aorta and into a distal apical branch of the LAD coronary artery to measure, respectively, aortic pressure (coronary perfusion pressure (PA), peripheral coronary pressure )PC), and coronary artery pressure gradient (PG = PA -PC). End-diastolic resistances to flow were computed as: (a) large coronary end-diastolic resistance (RL = PG/CBF), and (B) small coronary end-diastolic resistance (RS = PC/CBF). Nitroglycerine (NG) alone increased RL to approximately 180--220% of control and reduced RS to about 60% of control, respectively. Following pharmacologic blockade with propranolol (PRO), NG increased RL to about 180% of control and reduced RS to about 60% of control. Following alpha blockade with phenoxybenzamine (PBZ), NG decreased RL to about 78% of control and decreased RS to about 56% of control. It is concluded that while the overall effect of NG on the coronary vascular resistance is one of vasodilation, RL appears to be increased transiently and RS transiently decreased. Alpha adrenergic blockade appears to abolish this response. The increase in RL in response to NG appears to be associated with the systemic hypotensive effect in response to NG. It is proposed that the observed increase in RL is produced by the increase in cardiac sympathetic nerve activity which is initiated by the systemic hypotensive effect of NG.

Severe stenosis occurring in antibiotic sterilised homograft valves.

This paper describes 3 patients who developed late severe stenosis in fresh antibiotics sterilised homograft valves. Two were in the aortic position and one in the mitral. All 3 patients underwent successful reoperation. This complication has not been previously reported in valves prepared by this method.