Is angiotensin-converting enzyme inhibitor useful in a Japanese population for secondary prevention after acute myocardial infarction? A final report of the Japanese Acute Myocardial Infarction Prospective (JAMP) study

Funding and infrastructure among large-scale clinical trials examining cardiovascular diseases in Japan: evidence from a questionnaire survey

BACKGROUND

Large-scale clinical trials with thousands of participants are often needed to evaluate the risk reductions of cardiac events and/or death. Many recent clinical trials have evaluated the incidences of cardiac events using hard endpoints, especially in cardiovascular and metabolic medicine. A high investigation cost is involved in conducting a large-scale clinical trial, and obtaining sufficient funding is essential. The infrastructural environment of clinical trials is currently inadequate in Japan. We conducted a questionnaire-based survey to address this issue. The present study sought to clarify the current situation surrounding large-scale clinical trials in terms of funding and infrastructure, and to inform discussion about improving the financial and infrastructural situation for clinical trials.

METHODS

We sent questionnaires to 119 sponsors of large-scale clinical trials between August 2007 and December 2007, and between July 2009 and August 2009. Answers to each question were summarized and data were statistically analyzed.

RESULTS

We received responses from the sponsors of 63 (52.9%) out of 119 trials to which questionnaires were sent. The results revealed that 25 trials (39.7%) were funded by foundations, and 21 trials (33.3%) were funded by public agencies. All of the foundations involved in conducting clinical trials, where funding sources were specified, were funded by private organizations such as pharmaceutical companies. All of the clinical trials with a cost of JPY 300 million (USD 3.27 million) or more were funded by private organizations, and none were funded solely by public agencies. The sponsors of 23 trials (36.5%) responded that the trial was 'not registered' to clinical trial registry.

CONCLUSIONS

The questionnaire responses revealed that there were still many trials whose funding sources were unclear and many sponsors were unaware of their responsibilities in managing and/or financing the costs of clinical trials. These findings indicate that further discussion is required to establish appropriate frameworks and/or rules regarding funding, while considering conflicts of interest. This discussion should take place as soon as possible to facilitate appropriate clinical trials.

Limited accessibility to designs and results of Japanese large-scale clinical trials for cardiovascular diseases

BACKGROUND

Clinical evidence is important for improving the treatment of patients by health care providers. In the study of cardiovascular diseases, large-scale clinical trials involving thousands of participants are required to evaluate the risks of cardiac events and/or death. The problems encountered in conducting the Japanese Acute Myocardial Infarction Prospective (JAMP) study highlighted the difficulties involved in obtaining the financial and infrastructural resources necessary for conducting large-scale clinical trials. The objectives of the current study were: 1) to clarify the current funding and infrastructural environment surrounding large-scale clinical trials in cardiovascular and metabolic diseases in Japan, and 2) to find ways to improve the environment surrounding clinical trials in Japan more generally.

METHODS

We examined clinical trials examining cardiovascular diseases that evaluated true endpoints and involved 300 or more participants using Pub-Med, Ichushi (by the Japan Medical Abstracts Society, a non-profit organization), websites of related medical societies, the University Hospital Medical Information Network (UMIN) Clinical Trials Registry, and clinicaltrials.gov at three points in time: 30 November, 2004, 25 February, 2007 and 25 July, 2009.

RESULTS

We found a total of 152 trials that met our criteria for 'large-scale clinical trials' examining cardiovascular diseases in Japan. Of these, 72.4% were randomized controlled trials (RCTs). Of 152 trials, 9.2% of the trials examined more than 10,000 participants, and 42.8% examined between 1,000 and 10,000 participants. The number of large-scale clinical trials markedly increased from 2001 to 2004, but suddenly decreased in 2007, then began to increase again. Ischemic heart disease (39.5%) was the most common target disease. Most of the larger-scale trials were funded by private organizations such as pharmaceutical companies. The designs and results of 13 trials were not disclosed.

CONCLUSIONS

To improve the quality of clinical trials, all sponsors should register trials and disclose the funding sources before the enrolment of participants, and publish their results after the completion of each study.

Three therapeutic tendencies for secondary prevention of myocardial infarction and possible role of Chinese traditional patent medicine: viewpoint of evidence-based medicine

OBJECTIVE

The possibility of the preventive and therapeutic effects of Chinese traditional patent medicine for myocardial infarction has been reported in the literature, but there have been few studies. This paper presents three tendencies for the secondary prevention of myocardial infarction and presents a systematic evaluation of current research evidence related to the use of Chinese traditional patent medicine in secondary prevention of myocardial infarction, with a goal of making objective recommendations for patient rehabilitation.

METHOD

Literature was retrieved from traditional Chinese medicine websites, MEDLINE, CNKI, VIP, CINAHL, The Cochrane Library, EMBASE, HealthSTAR, and Academic ASAP to locate research-based scientific evidence related to the use of Chinese traditional patent medicine for myocardial infarction.

RESULTS

Some Chinese traditional patent medicine therapies alone or in combination with routine rehabilitation therapies might be useful in patients with myocardial infarction, but we found insufficient evidence to support the use of most Chinese traditional patent medicine therapies in the secondary prevention of myocardial infarction.

CONCLUSION

Difficulty in accessing information regarding traditional Chinese medicine has implications for health education in both myocardial infarction and patient safety. Some Chinese traditional patent medicine therapies hold promise for patients in the secondary prevention of myocardial infarction but further research is essential in all areas of traditional Chinese medicine to confirm its efficacy.

Effects of zofenopril on myocardial ischemia in post-myocardial infarction patients with preserved left ventricular function: the Survival of Myocardial Infarction Long-term Evaluation (SMILE)-ISCHEMIA study

BACKGROUND

The aim of the study was to investigate the cardioprotective effects of the angiotensin-converting enzyme inhibitor zofenopril in post-myocardial infarction (MI) patients with preserved left ventricular function (LVF).

METHODS

Three hundred forty-nine post-MI patients with preserved LVF (LV ejection fraction >40%) were treated for 6 months with zofenopril 30 to 60 mg (n = 177) or placebo (n = 172) according to a double-blind, randomized study design. The primary end point of the study was the combined occurrence of significant ST-T abnormalities on ambulatory electrocardiography (ECG), ECG abnormalities or symptoms of angina during standard exercise test, recurrence of MI, and need for revascularization procedures for angina.

RESULTS

The primary end point occurred in 20.3% of zofenopril-treated and 35.9% of placebo-treated patients (P = .001), despite no differences in blood pressure control, LVF, and concomitant therapy. ST-T depression during ambulatory ECG occurred in 22.7% of patients treated with placebo and 10.7% of those undergoing ACE-inhibition treatment (P = .027). ST-T depression in response to exercise test occurred in 14.2% and 26.7% of patients treated with zofenopril or placebo, respectively, (P = .024), with a lower proportion of zofenopril-treated patients who complained of anginal pain (4.7 vs 14.3%; P = .017), significant ST depression (14.2 vs 26.7%; P = .024), and major ventricular arrhythmias (3.8 vs 10.5%; P = .048). The rate of major cardiovascular events was reduced in patients treated with ACE inhibitor, with a lower rate of development and progression of congestive heart failure.

CONCLUSIONS

The results of the SMILE-ISCHEMIA study support the cardioprotective role of zofenopril when given to patients with normal LVF after acute MI.