Outcome in German and South African peripartum cardiomyopathy cohorts associates with medical therapy and fibrosis markers

Aims
This study aims to compare the clinical course of peripartum cardiomyopathy (PPCM) cohorts from Germany (G‐PPCM) and South Africa (SA‐PPCM) with fibrosis‐related markers to get insights into novel pathomechanisms of PPCM.

Methods and results
G‐PPCM (n = 79) and SA‐PPCM (n = 72) patients and healthy pregnancy‐matched women from Germany (n = 56) and South Africa (n = 40) were enrolled. Circulating levels of procollagen type‐I (PINP) and type‐III (PIIINP) N‐terminal propeptides, soluble ST2, galectin‐3, and full‐length and cleaved osteopontin (OPN) were measured at diagnosis (baseline) and 6 months of follow‐up. Both cohorts received standard heart failure therapy while anticoagulation therapy was applied in 100% of G‐PPCM but only in 7% of SA‐PPCM patients. In G‐PPCM patients, baseline left ventricular ejection fraction (LVEF) was lower, and outcome was better (baseline LVEF, 24 ± 8%, full recovery: 52%, mortality: 0%) compared with SA‐PPCM patients (baseline LVEF: 30 ± 9%, full recovery: 32%, mortality: 11%; P < 0.05). At baseline, PINP/PIIINP ratio was lower in SA‐PPCM and higher in G‐PPCM compared with respective controls, whereas total OPN was elevated in both collectives. Cleaved OPN, which increases PIIINP levels, is generated by thrombin and was reduced in patients receiving anticoagulation therapy. High baseline galectin‐3, soluble ST2, and OPN levels were associated with poor outcome in all PPCM patients.

Conclusions
SA‐PPCM patients displayed a more profibrotic biomarker profile, which was associated with a less favourable outcome despite better cardiac function at baseline, compared with G‐PPCM patients. Use of bromocriptine and anticoagulation therapy in G‐PPCM may counteract fibrosis and may in part be responsible for their better outcome.