Myocardial Infarction and Current Oral Contraceptive Use

To assess whether current oral contraceptive (OC) use (within the previous month) increased the risk of myocardial infarction. Also, to assess the combined effects of cigarette smoking and oral contraceptive use.

Study Overview

Detailed Description

BACKGROUND:

It has been established that oral contraceptive formulations used in the 1960s and 1970s increased the risks of myocardial infarction, venous thromboembolism, and stroke. Oral contraceptive formulations have changed, as have prescribing practices, and there was a need for information on the effects of the newer formulations in use. Myocardial infarction is the most important cardiovascular disease in terms of the incidence and mortality attributed to use of oral contraceptives; although the overall incidence of myocardial infarction is relatively low in women of childbearing ages, the incidence is not low in smokers.

DESIGN NARRATIVE:

A case-control design was used. The case series consisted of women 18 to 44 years of age admitted for a documented first myocardial infarction to any of 100 collaborating hospitals in Massachusetts, Rhode Island, and Pennsylvania. Nurse interviewers administered standard structured questionnaires to cases and controls on drug use, race, religion, medical history and myocardial infarction risk factors. Information was collected on: cigarette smoking; histories of hypertension, diabetes mellitus, angina, abnormal plasma lipids; reproductive and menstrual histories; alcohol and coffee consumption; personality type using the Framingham Type A scale; family history of myocardial infarction; exercise; education and occupation of the patient and her spouse. Information was also obtained on the timing and duration of oral contraceptive use. The effect of oral contraceptive use was considered among nonsmokers, light smokers, and heavy smokers. Individual oral contraceptive formulations were classified according to dosage and type of estrogen, formulation type, and other groupings. Multiple logistic regression analysis with fitting of the regression equations by the method of maximum likelihood was used for simultaneous control of all potential confounding factors.

The study was renewed in 1995 to continue data collection to establish the effect of triphasic OCs on MI risk, with particular attention to the joint effect with heavy smoking. The new data collection also permitted more definitive analysis of the effect of monophasic OCs. Triphasic formulations have become popular and in 1995 accounted for about half of OC use. There were not enough users of triphasic OCs in the present study for informative analysis, nor were there any data from other studies on this issue. The study ended in December, 1999.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

Study Type

Observational

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

No older than 100 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

No eligibility criteria

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

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Publications and helpful links

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Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

April 1, 1989

Study Completion (Actual)

December 1, 1999

Study Registration Dates

First Submitted

May 25, 2000

First Submitted That Met QC Criteria

May 25, 2000

First Posted (Estimate)

May 26, 2000

Study Record Updates

Last Update Posted (Estimate)

May 13, 2016

Last Update Submitted That Met QC Criteria

May 12, 2016

Last Verified

June 1, 2001

More Information

Terms related to this study

Other Study ID Numbers

  • 1122 (Jian-jun Li)
  • R01HL042483 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Myocardial Infarction

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