|Year : 2002 | Volume
| Issue : 2 | Page : 2
Jassim Al Suwaidi
|Date of Web Publication||22-Jun-2010|
Jassim Al Suwaidi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Al Suwaidi J. Cardiovascular News. Heart Views 2002;3:2
Primary angioplasty beneficial in elderly patients with acute myocardial infarction
A randomized comparison of primary angioplasty and thrombolytic therapy study sought to determine the short- and long-term outcome of primary coronary angioplasty and thrombolytic therapy for acute myocardial infarction (AMI) in patients older than 75 years of age. 87 patients with an AMI who were older than 75 years were randomly assigned to treatment with angioplasty or intravenous (IV) streptokinase. Clinical outcome was measured by taking the end points of death and the combination of death, reinfarction or stroke during follow-up. The primary end point, a composite of death, reinfarction or stroke, at 30 days had occurred in 4 (9%) patients in the angioplasty group as compared with 12 (29%) in the thrombolysis group (p = 0.01, relative risk [RR]: 4.3, 95% confidence interval [CI]: 1.2 to 20.0). At one year the corresponding figures were 6 (13%) and 18 (44%), respectively (p = 0.001, RR: 5.2, 95% CI: 1.7 to 18.1). The authors concluded that in patients with AMI who were older than 75 years, primary coronary angioplasty had a significant clinical benefit when compared with IV streptokinase therapy.
Obesity accelerates coronary atherosclerosis in young men
The Pathobiological Determinants of Atherosclerosis in Youth (PDAY) evaluated the association of obesity and atherosclerosis in young patients dying of external causes. The study collected arteries, blood, and other tissue from 3000 persons aged 15 to 34 years dying of external causes and autopsied in forensic laboratories. The investigators measured gross atherosclerotic lesions in the right coronary artery (RCA), American Heart Association (AHA) lesion grade in the left anterior descending coronary artery (LAD), serum lipid concentrations, serum thiocyanate (for smoking), intimal thickness of renal arteries (for hypertension), glycohemoglobin (for hyperglycemia), and adiposity by body mass index (BMI) and thickness of the panniculus adiposus. BMI in young men was associated with both fatty streaks and raised lesions in the RCA and with AHA grade and stenosis in the LAD. The effect of obesity (BMI>30 kg/m2) on RCA raised lesions was greater in young men with a thick panniculus adiposus. Obesity was associated with non-HDL and HDL (inversely) cholesterol concentrations, smoking (inversely), hypertension, and glycohemoglobin concentration. These variables accounted for 15% of the effect of obesity on coronary atherosclerosis in young men. BMI was not associated with coronary atherosclerosis in young women although there was a trend among those with a thick panniculus adiposus. The study concluded that obesity is associated with accelerated coronary atherosclerosis in adolescent and young adult men. These observations support the current emphasis on controlling obesity to prevent adult coronary heart disease.
Sirulimus-eluting stent reduces restenosis
Restenosis of a treated vessel remains the main limitation of percutaneous coronary revascularization. Sirolimus (rapamycin) inhibits the proliferation of lymphocytes and smooth-muscle cells. The RAVEL study compared a sirolimus-eluting stent with a standard uncoated stent in patients with angina pectoris. The investigators performed a randomized, double blind trial to compare the two types of stents for revascularization of single, primary lesions in native coronary arteries. The trial included 238 patients at 19 medical centers. The primary end point was in-stent late luminal loss (the difference between the minimal luminal diameter immediately after the procedure and the diameter at six months). Secondary end points included the percentage of in-stent stenosis of the luminal diameter and the rate of restenosis (luminal narrowing of 50 percent or more). The investigators analyzed the composite clinical end point consisting of death, myocardial infarction, and percutaneous or surgical revascularization at 1, 6, and 12 months. At six months, the degree of neointimal proliferation, manifested as the mean (SD) late luminal loss, was significantly lower in the sirolimus-stent group than in the standard-stent group (P<0.001). None of the patients in the sirolimus-stent group, as compared with 26.6 percent of those in the standard-stent group, had restenosis of 50 percent or more of the luminal diameter (P<0.001). There were no episodes of stent thrombosis. During a follow-up period of up to one year, the overall rate of major cardiac events was 5.8 percent in the sirolimus-stent group and 28.8 percent in the standard-stent group (P<0.001). The difference was due entirely to a higher rate of revascularization of the target vessel in the standard-stent group. The study concluded that a sirolimus-eluting stent shows considerable promise for the prevention of neointimal proliferation, restenosis, and associated clinical events.
Beta-blockers, sotalol, or amiodarone reduce postoperative atrial fibrillation
To better understand the role of various prophylactic therapies against postoperative atrial fibrillation (AF), Crystal et al conducted a systematic review of evidence from randomized trials. Fifty-two randomized trials (controlled by placebo or routine treatment) of b-blockers, sotalol, amiodarone, or pacing were identified by systematic literature search. Results of beta-blockers, sotalol, amiodarone, or pacing in preventing AF were analyzed. The 3 drug treatments each prevented AF. Pacing was also effective. The incidence of stroke was 1.2% in all the treatment groups combined and 1.4% in controls (OR, 0.90; 95% CI, 0.46 to 1.74). Beta-blockers, sotalol, and amiodarone all reduce risk of postoperative AF with no marked difference between them. There is evidence that use of these drugs will reduce LOS. Biatrial pacing is a promising new treatment. There was no evidence that reducing postoperative AF reduces stroke; however, data on stroke are incomplete.
Cardiac resynchronization beneficial in chronic heart failure
Previous studies have suggested that cardiac resynchronization achieved through atrial-synchronized biventricular pacing produces clinical benefits in patients with heart failure who have an intraventricular conduction delay. The investigators conducted a double-blind trial to evaluate this therapeutic approach. Four hundred fifty-three patients with moderate-to-severe symptoms of heart failure associated with an ejection fraction of 35 percent or less and a QRS interval of 130 msec or more were randomly assigned to a cardiac-resynchronization group (228 patients) or to a control group (225 patients) for six months, while conventional therapy for heart failure was maintained. The primary end points were the New York Heart Association functional class, quality of life, and the distance walked in six minutes. As compared with the control group, patients assigned to cardiac resynchronization experienced an improvement in the distance walked in six minutes (+39 vs. +10 m, P=0.005), functional class (P<0.001), quality of life (-18.0 vs. -9.0 points, P= 0.001), time on the treadmill during exercise testing (+81 vs. +19 sec, P=0.001), and ejection fraction (+4.6 percent vs. -0.2 percent, P<0.001). In addition, fewer patients in the group assigned to cardiac resynchronization than control patients required hospitalization (8 percent vs. 15 percent) or intravenous medications (7 percent vs. 15 percent) for the treatment of heart failure (P<0.05 for both comparisons). Implantation of the device was unsuccessful in 8 percent of patients and was complicated by refractory hypotension, bradycardia, or asystole in four patients (two of whom died) and by perforation of the coronary sinus requiring pericardiocentesis in two others. Cardiac resynchronization results in significant clinical improvement in patients who have moderate-to-severe heart failure and an intraventricular
Ventricular Pacing or Dual-Chamber Pacing for Sinus-Node Dysfunction
Dual-chamber (atrioventricular) and single-chamber (ventricular) pacing are alternative treatment approaches for sinus-node dysfunction that causes clinically significant bradycardia. However, it is unknown which type of pacing results in the better outcome. Gervasio and colleagues randomly assigned a total of 2010 patients with sinus-node dysfunction to dual-chamber pacing (1014 patients) or ventricular pacing (996 patients) and followed them for a median of 33.1 months. The primary end point was death from any cause or nonfatal stroke. Secondary end points included the composite of death, stroke, or hospitalization for heart failure; atrial fibrillation; heart-failure score; the pacemaker syndrome; and the quality of life. The incidence of the primary end point did not differ significantly between the dual-chamber group (21.5 percent) and the ventricular-paced group (23.0 percent, P=0.48). In patients assigned to dual-chamber pacing, the risk of atrial fibrillation was lower (hazard ratio, 0.79; 95 percent confidence interval, 0.66 to 0.94; P=0.008), and heart-failure scores were better (P<0.001). The differences in the rates of hospitalization for heart failure and of death, stroke, or hospitalization for heart failure were not significant in unadjusted analyses but became marginally significant in adjusted analyses. Dual-chamber pacing resulted in a small but measurable increase in the quality of life, as compared with ventricular pacing. The authors concluded that in sinus-node dysfunction, dual-chamber pacing does not improve stroke-free survival, as compared with ventricular pacing. However, dual-chamber pacing reduces the risk of atrial fibrillation, reduces signs and symptoms of heart failure, and slightly improves the quality of life. Overall, dual-chamber pacing offers significant improvement as compared with ventricular pacing.