CHRONIC TERBUTALINE THERAPY AND PERIPARTUM CARDIOMYOPATHY - A CASE-CONTROL STUDY

Objective: A previous case report (1) described 15 women with peripart um cardiomyopathy documented by clinical and ECHO criteria, 4 of whom had received terbutaline long term (range 9.5-53 days, mean 4.2 +/- 2. 6 weeks) for premature labor. To further explore the significance of t his observation a case-control study was designed specifically inquiri ng whether long-term beta-Mimetic therapy of at least 9 days duration for preterm contractions is associated with subsequent development of peripartum cardiomyopathy. Methods: Controls for the 15 cardiomyopathi c patients were chosen by computer-generated random patient unit numbe r selection from all deliveries occurring in the period 1985-1991. Med ical records were reviewed to determine exposure to terbutaline and ot her tocolytics, as well as potentially confounding factors. A logistic regression analysis of the data was performed and adjusted odds ratio s (OR) and 95% confidence intervals (Cf)were calculated for the covari ates.Main Outcome Measure: Quantitation of exposure to beta-mimetic ag ents in peripartum cardiomyopathy patients and patients without this d isease. Results: While 4 (26.7%) of the original 15 cases had received long-term terbutaline therapy, only 3 (5.0%) of 60 controls did. The potentially confounding variables were smoking and maternal age, but e ven when these were controlled, terbutaline therapy remained significa ntly associated with the development of peripartum cardiomyopathy, OR 6.91 (1.30-36.85), P = 0.02. Conclusion: These data suggest a relation ship between long-term terbutaline therapy for preterm labor and subse quent development of peripartum cardiomyopathy.