The prolactine hypothesis for peripartum cardiomyopathy: has it found its feet for good?

Background Peripartum cardiomyopathy (PPCM) is a rare but serious condition that affects childbearing women. Dopamine agonists (DAs) may represent a specific therapy, potentially facilitating left ventricular recovery, through inhibition of prolactin secretion. However, their therapeutic value in this setting has not been fully demonstrated. Purpose To perform a meta-analysis aimed at evaluating the extent to which DAs are able to interfere with the natural history of PPCM. Methods We systematically searched MEDLINE, Embase, Web of Science, Cochrane Library, Google Scholar, Scopus and DARE for both randomized controlled trials (RCTs) and observational studies addressing the impact of DAs on main outcomes of PPCM patients, published up until February 1, 2020. Endpoints were those of mortality, recovery from heart failure and, likewise, the degree to which left ventricular ejection fraction (LVEF) was restored. All analyses were conducted under a DA plus optimized medical therapy (OMT) vs. OMT alone design, while results were pooled using traditional meta-analytic techniques, under a random-effects model. Odds ratios (ORs) were computed for the first two outcomes, whereas mean difference (MD) was calculated to quantify LVEF restoration. Results 2 RCTs, 2 prospective cohort, 1 prospective case-control and 2 retrospective cohort studies, encompassing 452 patients, were regarded as eligible for quantitative evaluation. 180 patients were allocated to the DA arm, which was mostly represented by bromocriptine; in fact, only 1 study, including 24 patients, specified cabergolin utilization. Overall, 5 papers including 295 patients reported 42 deaths, whereas 5 papers comprising 305 patients detailed 220 heart failure recoveries, thus unveiling that LVEF restoration was the norm. The addition of a DA to OMT provided no signal of a survival benefit (OR 0.71, 95% CI 0.27–1.87, p=0.49, i2=27%). On the other hand, the incorporation of a DA into the therapeutic regimen narrowly missed significance for the heart failure recovery endpoint (OR 2.68, 95% CI 0.98–7.31, p=0.05, i2=56%). Furthermore, DAs were demonstrated to incrementally improve LVEF by 15% (MD 15.00, 95% CI 10.24–19.76, p Conclusion In PPCM patients, the addition of a DA to OMT seems to be both effective at incrementally improving LVEF and safe, even though not reaching survival benefit status. These findings appear to corroborate the so-called prolactin hypothesis for PPCM pathophysiology. Funding Acknowledgement Type of funding source: None