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Myocardial Infarction and Current Oral Contraceptive Use

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ClinicalTrials.gov Identifier: NCT00005241
Recruitment Status : Completed
First Posted : May 26, 2000
Last Update Posted : May 13, 2016
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)

Brief Summary:
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.

Condition or disease
Cardiovascular Diseases Coronary Disease Myocardial Infarction Heart Diseases

Detailed Description:


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.


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
Study Start Date : April 1989
Study Completion Date : December 1999

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Heart Attack
U.S. FDA Resources

Information from the National Library of Medicine

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Ages Eligible for Study:   up to 100 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
No eligibility criteria

ClinicalTrials.gov Identifier: NCT00005241     History of Changes
Other Study ID Numbers: 1122
R01HL042483 ( U.S. NIH Grant/Contract )
First Posted: May 26, 2000    Key Record Dates
Last Update Posted: May 13, 2016
Last Verified: June 2001

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases
Myocardial Infarction
Coronary Disease
Coronary Artery Disease
Pathologic Processes
Myocardial Ischemia
Vascular Diseases
Arterial Occlusive Diseases