Background: Peripartum cardiomyopathy (PPCM) is characterized by heart failure. Our previous study found that autoantibodies against the M2-muscarinic receptor (anti-M2-R) are increased in PPCM patients. We aimed to evaluate the association of anti-M2-R on prognosis of PPCM patients with standard treatment.
Methods: Synthetic peptides corresponding to the M2 receptor served as the target antigens in an enzyme-linked immunosorbent assay experiment. They were used to screen the sera of 80 PPCM patients, who were separated into anti-M2-R-negative and positive groups according to their anti-M2-R reactivity. Clinical assessment and echocardiography examination were performed at baseline and after 5 years with a standard treatment regimen. The endpoint events were compared after 5 years of follow-up.
Results: There were 76 PPCM patients who completed the final data analysis, including 36 in the anti-M2-R (+) group and 40 in the anti-M2-R (-) group. Both groups showed improvement in the left ventricular end-diastolic and end-systolic dimensions and the ejection fraction with standard treatment regimens for 5 years (all p<0.001). Patients in the anti-M2-R (-) group had greater tolerance and were more rapidly titrated to metoprolol, and they had better improvement in cardiac function than patients in the anti-M2-R (+) group (p<0.05). Patients in the anti-M2-R (-) group had a marked decrease in re-hospitalization (p<0.05), but not in all-cause mortality or cardiovascular mortality. Being positive for anti-M2-R increased the risk of PPCM (OR=4.7, 95% CI 1.8-12.2, p=0.002).
Conclusions: PPCM patients, especially anti-M2-R (-) patients, have a relatively better prognosis than other patients. We posit that the presence of anti-M2-R may be involved in the pathogenesis of PPCM.
Keywords: Anti-M2-muscarinic receptor; Congestive heart failure; Peripartum cardiomyopathy; Prognosis.
Copyright © 2019. Published by Elsevier Ltd.