Percutaneous coronary intervention versus coronary artery bypass graft surgery for patients with medically refractory myocardial ischemia and risk factors for adverse outcomes with bypass: a multicenter, randomized trial. Investigators of the Department of Veterans Affairs Cooperative Study #385, the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME).

BACKGROUND: Percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (CABG) are being applied to high-risk populations, but previous randomized trials comparing revascularization methods have excluded a number of important high-risk groups. OBJECTIVES: This five-year, multicenter, randomized clinical trial was designed to compare long-term survival among patients with medically refractory myocardial ischemia and a high risk of adverse outcomes assigned to either a CABG or a PCI strategy, which could include stents. METHODS: Patients from 16 Veterans Affairs Medical Centers were screened to identify myocardial ischemia refractory to medical management and the presence of one or more risk factors for adverse outcome with CABG, including prior open-heart surgery, age >70 years, left ventricular ejection fraction <0.35, myocardial infarction within seven days or intraaortic balloon pump required. Clinically eligible patients (n = 2,431) underwent coronary angiography; 781 were angiographically acceptable; 454 (58% of eligible) patients consented to random assignment between CABG and PCI. RESULTS: A total of 232 patients was randomized to CABG and 222 to PCI. The 30-day survivals for CABG and PCI were 95% and 97%, respectively. Survival rates for CABG and PCI were 90% versus 94% at six months and 79% versus 80% at 36 months (log-rank test, p = 0.46). CONCLUSIONS: Percutaneous coronary intervention is an alternative to CABG for patients with medically refractory myocardial ischemia and a high risk of adverse outcomes with CABG.

A multicenter, randomized trial of percutaneous coronary intervention versus bypass surgery in high-risk unstable angina patients. The AWESOME (Veterans Affairs Cooperative Study #385, angina with extremely serious operative mortality evaluation) investigators from the Cooperative Studies Program of the Department of Veterans Affairs.

This multicenter, prospective randomized trial was designed to test the hypotheses that percutaneous coronary intervention (PCI) is a safe and effective alternative to coronary artery bypass grafting (CABG) for patients with refractory ischemia and high risk of adverse outcomes. As a comparison of revascularization strategies, the trial specifically allows surgeons and interventionists to use new techniques as they become clinically available. After 42 months of this 72-month trial, 17,624 patients have been screened and 2022 met eligibility requirements: 341 have been randomized to either CABG or PCI, and the remaining 1681 are being prospectively followed in a registry. The 3-year overall survival of patients in the registry and randomized trial is comparable. To enhance accrual into the randomized trial, site visits were conducted, a few low-accruing hospitals were put on probation and/or replaced, eligibility criteria were reviewed at annual meetings of investigators, and the accrual period was extended by 1 year. These data demonstrate that a prospective randomized trial and registry of coronary revascularization for medically refractory high-risk patients is feasible.

Systolic blood pressure response to percutaneous transluminal coronary angioplasty for cardiogenic shock.

This study reports that an improvement in systolic blood pressure of > 10 mm Hg after PTCA in patients with cardiogenic shock was associated with in-hospital survival (8 of 8 patients). Failure to achieve infarct artery patency (6 of 6) or technically successful PTCA, unaccompanied by improved systolic blood pressure in the catheterization laboratory, was associated with in-hospital mortality in this series.

Percutaneous transluminal angioplasty of saphenous vein grafts for medically refractory unstable angina.

OBJECTIVES: We attempted to answer the question, Is balloon angioplasty a reasonable alternative to repeat coronary artery bypass graft surgery in patients with previous coronary bypass graft surgery, medically refractory unstable angina and vein graft lesions? BACKGROUND: Patients with medically refractory unstable angina need revascularization. Patients with previous coronary artery bypass graft surgery and medically refractory angina are at "high risk" for adverse outcomes with repeat coronary bypass graft surgery. Conversely, patients with angioplasty of old vein grafts are also at "high risk" for adverse outcomes. METHODS: Balloon angioplasty of 89 lesions in saphenous vein grafts was performed in 75 consecutive patients with medically refractory unstable angina. Of these 75 patients, 24 (32%) had myocardial infarct within 30 days, 23 (31%) had left ventricular ejection fraction < 0.35, and 50 (67%) had major comorbidity. Patients underwent standard balloon angioplasty with aggressive use of intravenous and intracoronary heparin, urokinase, nitroglycerin, oral aspirin, calcium channel blocking agents and coumadin. RESULTS: Angiographic success (reduction of stenosis < or = 50% without major complication) was seen in 84 of 89 lesions. Clinical success (angiographic success plus hospital discharge without major complication) was seen in 70 of 75 patients. During index hospitalization, two patients (3%) died, two (3%) had nonfatal infarcts, and one (1%) had emergency reoperation (coronary bypass graft surgery). In late follow up (3 to 66 months), 14 (20%) patients were lost to follow-up, 17 (23%) had repeat percutaneous transluminal coronary angioplasty, 2 (3%) had late bypass graft reoperation, 18 (25%) had late death, and 1 (< 1%) had a heart transplant. Of the 41 patients alive after one or more angioplasties, 25 have little or no angina, and 16 have occasional or more angina. We compared long-term survival rate in these 75 patients with a cohort of patients with high risk, unstable angina from the Veterans Affairs Surgical Registry (2,570 patients). The 30-day survival rate was better in patients with coronary angioplasty (97% vs. 92%, p < 0.05), but by 6 months there was no difference, and by 5 years a trend toward a higher survival rate with coronary artery bypass graft surgery was seen. CONCLUSIONS: Balloon angioplasty of saphenous vein grafts with aggressive adjunctive pharmacotherapy is a reasonable alternative to repeat coronary bypass graft surgery in patients with medically refractory unstable angina, previous coronary bypass graft surgery and saphenous vein narrowing.

Salvage angioplasty: an alternative to high risk surgery for unstable angina?

This prospective, Human Subjects Committee and Ethics Committee approved investigation was performed to determine if coronary angioplasty (PTCA) might be a reasonable alternative revascularization method for unstable angina patients thought to be at high risk for operative (CABG) mortality. Between March 1990 and October 1991, thirty-four consecutive patients with medically refractory rest angina were deamed to have high risk of surgical mortality and underwent PTCA without surgical backup. Predicted operative mortality was calculated for each patient based upon the VA Surgical Risk Assessment model. Angioplasty of 52 vessels was attempted. Reduction in lumenal narrowing to < 50% and improved angiographic flow was obtained in 47 vessels. There were four complicating infarctions. One death occurred in the lab, and three patients with unsuccessful angioplasty died within 30 days of pump failure. Relief of angina occurred in 30/34. Thirty patients were discharged home. In follow-up from 1 to 12 months, there have been 2 late sudden deaths at 4 months and 9 months, 1 death from lung cancer; 4 patients have stable exertional angina; 2 are awaiting heart transplant but are pain free, and one patient who had PTCA during cardiogenic shock from acute myocardial infarction had elective coronary artery bypass surgery. There have been no late myocardial infarctions. The observed angioplasty 30-day mortality of 11.8% (95% confidence limit 1% to 22.6%) compares favorably with the predicted operative mortality of 23.8% for this group. This prospective but non-randomized series supports the concept that balloon angioplasty may be a reasonable alternative to surgical intervention in some patients with unstable angina and high risk for surgery. A prospective randomized trial is warranted.

Automated external defibrillators: an update of additions to the ACLS algorithms.

Instruction in the use of the automated external defibrillator is now a mandatory component of ACLS certification. Here's a review of changes to the ACLS algorithm.

Pulmonary vascular impedance and wave reflections in the hypoxic calf.

The alterations in pulsatile hemodynamics that occur during hypoxic pulmonary vasoconstriction have not been well characterized. Changes in oscillatory hemodynamics, however, may affect right ventricular-pulmonary vascular coupling and the dissipation of energy within the lung vasculature. To better define hypoxic pulsatile hemodynamics, we measured main pulmonary artery proximal and distal micromanometric pressures and ultrasonic flow in four open-chest calves during progressive hypoxia. Main pulmonary artery impedance and pressure transmission spectra were calculated using spectral analysis methods. Measured pressure and flow signals were separated in the time domain into forward and backward components. Hypoxia increased pulmonary blood pressure and resistance and produced multiple modifications in the impedance and pressure transmission spectra that indicated increased wave reflections and elasticity. The impedance and apparent phase velocity first-harmonic values were increased in amplitude, and the pressure transmission modulus plot showed an increased peak value. In addition, the impedance modulus plot demonstrated a rightward shift and increased oscillation in the mid- to high-frequency range. The time domain analysis also confirmed increased wave reflections and elasticity. Hypoxia produced large backward-traveling (reflected) pressure and flow waves. The initial portions of these waves arrived at the heart during systole, producing characteristic changes in the measured pressure and flow waveforms. With prolonged hypoxia, main pulmonary artery pulse wave velocity increased by 30%. Thus, hypoxia is associated with complex alterations in pulmonary artery elasticity and wave reflections that act to increase the oscillatory afterload of the right ventricle.

Left and right ventricular systolic function and exercise capacity with coronary artery disease.

This prospective study of symptom-limited supine ergometry was conducted to determine the contributions of right ventricular (RV) and left ventricular (LV) systolic function to the exercise capacity of a cohort of patients with coronary artery disease (CAD). Patients with unstable angina, angiographically proven CAD (n = 53) and stable symptoms after medical therapy or angioplasty were included. Documented myocardial infarction (greater than or equal to 2 weeks before exercise) was present in 43 of 53 patients. Angina was the limiting symptom in 11 of 53; the other 42 stopped exercise with dyspnea or fatigue, or both. Oxygen consumption was measured on-line during exercise with a metabolic cart. RV ejection fraction and LV ejection fraction were measured by validated methods from gated blood pool radionuclide ventriculography. There were weak but statistically significant correlations between exercise oxygen consumption and exercise RV ejection fraction (r = 0.30, p less than 0.05) and between exercise oxygen consumption and exercise LV ejection fraction (r = 0.38, p less than 0.01). Multivariate regression analysis, including exercise RV ejection fraction, exercise LV ejection fraction and exercise heart rate versus exercise oxygen consumption revealed a better relation (r = 0.48, p less than 0.005) than any variable in univariate regression. The values of RV and LV ejection fraction at rest did not correlate significantly (r = 0.2, difference not significant), but the exercise values did correlate weakly (r = 0.41, p less than 0.01). The reserve of LV ejection fraction, defined as exercise minus rest value, correlated weakly with exercise oxygen consumption (r = 0.32, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Short day induced gonadal regression in ring doves (Streptopelia risoria): a case for seasonal variation.

Changes in follicular size (in diameter) were studied by laparotomy under various photoperiodic regimes in the domesticated ring doves that have been kept under standard laboratory conditions for generations. Follicular response shows two distinct patterns: 1. a shift from standard laboratory photoperiodic regime (LD 14:10) to extra long day (LD 20:4) accelerated the follicular development in the spring as well as in the autumn; 2. a shift from the standard laboratory photoperiodic regime (LD 14:10) to short day (LD 8:16 or LD 1/2:23 1/2) induced follicular regressions in the autumn but not in the spring. We propose that there is a responsive phase (spring) and nonresponsive phase (autumn) of hypothalamo-hypophyseal-ovarian system in the ring doves. Comparison of radioimmunoassay of pituitary and plasma LH value suggests that the responsive and non-responsive phase involves mainly release mechanisms. In the autumn, the release mechanism becomes insensitive to stimuli below certain thresholds. Our ring doves are kept in responsive phase throughout the year under the long photoperiodicity (LD 14:10). However, the effect of long day does not appear to override completely the seasonal effect.