The case of GISSI in changing the attitudes and practice of Italian cardiologists

Low-dose aspirin and vitamin E in people at cardiovascular risk: a randomised trial in general practice. Collaborative Group of the Primary Prevention Project

BACKGROUND

In addition to the treatment of specific cardiovascular risk factors, intervention which interferes with the general mechanisms of atherosclerosis could further reduce the incidence of cardiovascular events. We aimed to investigate in general practice the efficacy of antiplatelets and antioxidants in primary prevention of cardiovascular events in people with one or more major cardiovascular risk factors.

METHODS

We did a randomised controlled open 2x2 factorial trial to investigate low-dose aspirin (100 mg/day) and vitamin E (300 mg/day) in the prevention of cardiovascular events, in people with one or more of the following: hypertension, hypercholesterolaemia, diabetes, obesity, family history of premature myocardial infarction, or individuals who were elderly.

FINDINGS

4495 people (2583 female, mean age 64.4 years) were included in the trial. After a mean follow-up of 3.6 years the trial was prematurely stopped on ethical grounds when newly available evidence from other trials on the benefit of aspirin in primary prevention was strictly consistent with the results of the second planned interim analysis. Aspirin lowered the frequency of all the endpoints, being significant for cardiovascular death (from 1.4 to 0.8%; relative risk 0.56 [95% CI 0.31-0.99]) and total cardiovascular events (from 8.2 to 6.3%; 0.77 [0.62-0.95]). Severe bleedings were more frequent in the aspirin group than the no-aspirin group (1.1% vs 0.3%; p<0.0008). Vitamin E showed no effect on any prespecified endpoint. Analyses were by intention-to-treat.

INTERPRETATION

In women and men at risk of having a cardiovascular event because of the presence of at least one major risk factor, low-dose aspirin given in addition to treatment of specific risk factors contributes an additional preventive effect, with an acceptable safety profile. The results on vitamin E's cardiovascular primary preventive efficacy are not conclusive per se, although our results are consistent with the negative results of other large published trials on secondary prevention.

Influence of a randomized clinical trial on practice by participating investigators: lessons from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT). CAVEAT I and II Investigators

OBJECTIVES

We sought to determine whether the results of the first Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) influenced subsequent practice patterns among the investigators.

BACKGROUND

CAVEAT-I demonstrated that directional coronary atherectomy (DCA) resulted in higher rates of early complications at a higher cost and with no clinical benefit. We sought to determine whether these results influenced subsequent use of procedures among CAVEAT-I investigators.

METHODS

We compared the results of a week-long registry of all coronary interventions performed at 35 CAVEAT-I sites in 1994 with those of a similar registry obtained in 1992 before the trial, the results of which were published in 1993. For control purposes, the use of procedures was studied at 24 additional sites to provide insight into practice at hospitals not participating in the trial. A total of 1,465 interventions were analyzed.

RESULTS

Ninety-four percent of CAVEAT-I sites responded. Utilization rates differed between CAVEAT-I and CAVEAT-I follow-up (p < 0.001). Balloon angioplasty decreased from 83.8% to 68.5%, DCA increased slightly from 10.7% to 14.1%, and the use of other devices increased from 5.4% to 17.5%. Stand-alone balloon use was more prevalent at nonparticipating control sites than at sites that took part in CAVEAT-I (p < 0.001).

CONCLUSIONS

Paradoxically, despite the negative findings of CAVEAT-I, there was a noteworthy trend toward an increase in the use of DCA and other devices at CAVEAT-I sites. Our findings suggest that among investigators in the trial, there may have been a lack of influence of trial data on clinical practice patterns 1 year after publication of the results. Ethics of protocol: Both CAVEAT I and II were approved by the Institutional Review Board at each study site.

Feasibility of randomised clinical trials in rare diseases: the case of polycythemia vera

Although it has long been recognised as the only reliable instrument for producing scientific evidence on the benefit/risk profile of therapeutic interventions, the technology of randomised clinical trials (RCT) is far from being the backbone of medical knowledge. Randomised clinical trials in polycythemia vera have been carried out when their methodology was being built up and, therefore, was rather unsatisfactory. Now we have aggressive cytoreductive treatments with chemotherapeutic agents loaded with doubts on long-term safety, while phlebotomy and preventive antiplatelet therapy are left to personal preferences because of debatable results of old, low-power clinical trials. A complex profile of uncertainties requires a simple, but articulated strategy of care and research to allow at the same time a reasonable transfer of the best available validated knowledge and a timely investigation of the most relevant questions. Without doubts, multi-country, collaborative RCTs is the key (not isolated or abstract) element of the current scenario. The declared background hypothesis is the willingness of a medical caring community of being, at the same time and with the same patients, a research community. The trial design comes in as the simplest technical way to deal with uncertainty. Data to be collected, criteria, contents, intensity of follow-up, and documentation of the events are exactly the same as those which are planned and adopted in routine care. One of the greatest achievements of the multicenter trials with this orientation has been to produce a "core" of data and practices, on which the main analyses will be made, but which at the same time reflect an optimal level of assistance to the majority of patients. The purpose of this paper is therefore twofold: a) to provide a brief methodological review of the controlled evidence available for the direction of therapeutic practice for PV: b) to outline and discuss the opportunity, general design, and feasibility of research strategies where a comparative large-scale trial between therapeutic alternatives could play a central role.

Acute myocardial infarction treatments in 58 Italian hospitals: a drug utilization survey

OBJECTIVES

To provide an updated and comprehensive profile of therapeutic practice in the management of acute myocardial infarction (AMI) in a sample of Italian hospitals, and to test the possible role of a network of hospital pharmacists in providing drug utilization data.

DESIGN

Prospective drug utilization survey. Participating pharmacists collected information on patients consecutively admitted to the hospital with a suspected AMI. The form reproduced those adopted in the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico trials.

SETTING

Fifty-eight general hospitals in Italy belonging to the National Health Service, 6 of which are teaching hospitals. Thirty-four hospitals recruited patients from a coronary care unit, 10 from intensive monitoring beds in cardiology wards, and 14 from an intensive care unit.

PARTICIPANTS

The study population consisted of patients consecutively admitted with a suspected AMI from May 31 through July 5, 1993.

MAIN OUTCOME MEASURES

The management of AMI in terms of the use of drugs and nonpharmacologic treatments is described.

RESULTS

Of the 676 patients recruited for the study, 47.8% received thrombolytic therapy; alteplase was the preferred agent (55.4% of treated patients). The use of thrombolytic therapy varied significantly according to different demographic and clinical parameters such as age, sex, delay from the onset of symptoms to admission, and Killip scale class. During the first day of hospitalization 63.9% of patients received aspirin, 83.3% received nitrates, 24.8% received beta-blockers, and 77.1% received heparin therapy.

CONCLUSIONS

Thrombolytic therapy was prescribed in a higher percentage of patients than is reported in the US, but lower than that reported in large trials. That a low percentage of patients who experienced a long delay between the onset of symptoms and admission as well as elderly patients received thrombolytic therapy reflects the lower expectations of clinicians for these subgroups of patients. A low proportion of patients received aspirin therapy. This study showed that in Italy an institutional network of hospital pharmacists could be interested observers of therapeutic practice, but further training is needed before high-quality data can be collected.

Knowledge and practices of generalist and specialist physicians regarding drug therapy for acute myocardial infarction

BACKGROUND

The respective roles of generalist and specialist physicians in the care of patients is currently a matter of debate. Information is limited about the knowledge and practices of generalist and specialist physicians regarding conditions that both groups treat, such as myocardial infarction.

METHODS

We therefore surveyed 1211 cardiologists, internists, and family practitioners in the states of New York and Texas about four treatments demonstrated by randomized clinical trials to be associated with improved survival after myocardial infarction (thrombolytic therapy, immediate and long-term use of aspirin, and long-term use of beta-blockers) and two treatments for which such evidence is lacking (diltiazem for patients with pulmonary congestion and prophylactic lidocaine). We asked physicians about the effect of each treatment on survival and the likelihood that they would prescribe each class of drugs.

RESULTS

For the four beneficial treatments, the cardiologists believed more strongly than the internists and family physicians that survival was improved by the treatment, and they were more likely to prescribe these drugs (P < 0.001). For example, 94.1 percent of cardiologists said they were very likely to prescribe thrombolytic agents to treat an acute myocardial infarction, as compared with 82.0 percent of internists and 77.3 percent of family practitioners. Conversely, for the two treatments for which trials showed no evidence of a survival benefit, cardiologists were less likely than internists and family practitioners to think there was such a benefit and less likely to prescribe the drugs (P < 0.001). For example, 4.7 percent of cardiologists reported that they were very likely to use prophylactic lidocaine, as compared with 13.1 percent of internists, and 16.5 percent of family practitioners. When we used logistic regression to adjust for potential confounders, all the differences between the cardiologists and the internists and family practitioners remained significant (P < 0.02).

CONCLUSIONS

Internists and family practitioners are less aware of or less certain about key advances in the treatment of myocardial infarction than are cardiologists. This finding underscores the need to improve the dissemination of information from clinical trials to generalist physicians, particularly if they are to have an enlarged role in the evolving health care system.

Analytic epidemiology in psoriasis

The cause of psoriasis has only recently been subject to structured epidemiologic research approach. This is reflected in the scarcity of quantitative knowledge about etiologic factors for psoriasis other than genetics. A schematic model suggests that susceptibility to develop psoriatic lesions includes both genetic and extragenetic predisposing factors. Expression in terms of visible lesions is modulated by precipitating or trigger factors. Unlike many chronic diseases, psoriasis spontaneously waxes and wanes. When assessing factors that trigger the onset of the disease, one must also consider factors that lead to recurrence or exacerbation. Cohort and case-control studies are the main methodologic options for risk assessment. Combination of these techniques and the merging of an epidemiologic approach with basic biologic research are suggested routes to valuable results in this area.

Intercept studies, clinical trials, and cluster experiments: to whom can we extrapolate?

While sample surveys rely on an explicit theory of the relationship between a sample and its reference population, many nonsurvey-based designs lack a clear relationship to the population to which inferences are to be drawn. For example, in order to be applicable to large populations, intercept studies--which include observational studies of migrant populations and randomized studies such as mall intercepts--must make implicit or explicit assumptions about the probability of finding members of the population. In conducting clinical trials, constraints imposed by the research often lead large segments of the population to have zero probability of observation. Although such experiments generally conduct research at only a few sites, investigators usually intend to apply their results quite broadly. This paper compares intercept studies and clinical trials with particular emphasis on inference to a population for which the probabilities of being observed are unknown, unreliable, or very small.