Carlos A. Bertolasi

A new scoring system to stratify risk in unstable angina

BackgroundWe performed this study to develop a new scoring system to stratify different levels of risk in patients admitted to hospital with a diagnosis of unstable angina (UA), which is a complex syndrome that encompasses different outcomes. Many prognostic variables have been described but few efforts have been made to group them in order to enhance their individual predictive power.MethodsIn a first phase, 473 patients were prospectively analyzed to determine which factors were significantly associated with the in-hospital occurrence of refractory ischemia, acute myocardial infarction (AMI) or death. A risk score ranging from 0 to 10 points was developed using a multivariate analysis. In a second phase, such score was validated in a new sample of 242 patients and it was finally applied to the entire population (n = 715).ResultsST-segment deviation on the electrocardiogram, age ≥ 70 years, previous bypass surgery and troponin T ≥ 0.1 ng/mL were found as independent prognostic variables. A clear distinction was shown among categories of low, intermediate and high risk, defined according to the risk score. The incidence of the triple end-point was 6 %, 19.2 % and 44.7 % respectively, and the figures for AMI or death were 2 %, 11.4 % and 27.6 % respectively (p < 0.001).ConclusionsThis new scoring system is simple and easy to achieve. It allows a very good stratification of risk in patients having a clinical diagnosis of UA. They may be divided in three categories, which could be of help in the decision-making process.

Exercise training and heparin pretreatment in patients with coronary artery disease

The purpose of this study was to evaluate whether combined treatment with a cardiovascular exercise rehabilitation program and low doses of heparin can induce changes in ergometric parameters of ischemia in patients with coronary artery disease (CAD). Heparin may potentiate the development of new vessels promoted by ischemia and therefore may produce important clinical improvement. Thirty-six patients with stable CAD and evidence of myocardial ischemia on exercise testing were randomized into three groups: a control group (n = 11) received the usual medical treatment; another group (n = 11) underwent three exercise sessions per week during 12 weeks; and a third group (n = 14) undertook this exercise program and also received calcium heparin 12,500 IU subcutaneously 20 to 30 minutes before each exercise session. Pretreatment and posttreatment exercise tests were compared. Patients who underwent the rehabilitation program had an increase in exercise duration and workload at the onset of 1 mm ST-segment depression, but only patients who received calcium heparin showed a significant increase in rate-pressure product at the ST-segment ischemic threshold (p = 0.035). This result suggests that higher levels of myocardial oxygen consumption were now tolerated, a change that may be related to an improvement in myocardial perfusion.

Efficacy of flecainide in the management of ventricular arrhythmias: comparative study with amiodarone.

The effects on ventricular arrhythmias of a new class IA drug, flecainide, were compared with those of amiodarone in 10 patients with frequent, chronic, and stable ventricular ectopic beats (VEBs). The study consisted of an initial 1-week, placebo-controlled, baseline period followed by two 12-day, randomized, crossover, double-blind treatment periods with incremental dosage and 1 month of placebo between drug periods. Frequent VEBs, which were present in all 10 patients during both placebo control periods (30 or more VEBs/hour every hour, during 24-hour Holter monitoring), were markedly suppressed (reduction greater than 80%) in nine patients with both drugs (p less than 0.01). There was almost total abolition of the VEBs in six patients with flecainide, and the satisfactory results with a minimal dose in three demonstrate its fast onset of action. Side effects from either agent were infrequent and no discontinuation was necessary. We conclude from our study that flecainide is a highly effective antiarrhythmic agent.

Acute myocardial infarction-related coronary artery residual narrowing after intravenous streptokinase: Relationship with previous coronary symptoms

In 72 patients who received streptokinase within 6 hours of the onset of an acute myocardial infarction (AMI), the relationship between the presence of a previous coronary event and the severity of the residual coronary artery stenosis was studied. Fifty-five patients were either asymptomatic or had recent onset angina (less than 5 days) before AMI (group A) and 17 patients had chronic angina (greater than 1 year) before AMI (group B). Coronary angiograms were performed at 20 days (range 15 to 25 days). Patency of the infarct-related artery was greater in group A: 43 of 55 patients (78%) versus 8 of 17 patients (47%) in group B (p less than 0.05). Residual stenosis was less than 70% in 21 patients of group A (49% of patent arteries), whereas it manifested in none of eight patients with patent arteries in group B (p less than 0.01). This suggests that thrombosis was a major component of the coronary artery narrowing in group A patients, while it is more likely that thrombus only completes a previously severe (greater than 70%) coronary artery stenosis in patients with long-standing angina before AMI.