Abstract 4354619: Impact of delayed diagnosis and suboptimal therapy on mortality in peripartum cardiomyopathy: findings from a multicenter prospective Tanzanian cohort.

Background: Sub-Saharan Africa bears the highest burden of peripartum cardiomyopathy (PPCM), where the condition is often underdiagnosed, misdiagnosed, undertreated, or inappropriately managed due to symptom overlap with normal pregnancy, limited provider awareness, and inadequate access to cardiac diagnostics. Delayed diagnosis and suboptimal initiation of guideline-directed medical therapy (GDMT) likely contribute to poor outcomes. We investigated the impact of these delays on survival in a large, multicentre prospective PPCM cohort in Tanzania. Hypothesis: Delayed diagnosis and suboptimal initiation of GDMT are associated with increased mortality in women with PPCM. Methods: We analysed data from women meeting PPCM criteria enrolled prospectively from April 2016 across multiple Tanzanian centres. Delayed diagnosis was defined as PPCM diagnosed >3 months after symptom onset based on patient history and records. Suboptimal GDMT was defined as absence of one or more indicated heart failure medications (beta-blocker, ACE inhibitor/ARB, or MRA) in non-pregnant women with LVEF <45% without contraindications. In pregnant/breastfeeding women, failure to initiate beta-blockers and diuretics when indicated was considered suboptimal. Outcomes included mortality, complete recovery (LVEF >55%), and persistent dysfunction. Cox proportional hazards regression identified independent mortality predictors. Results: Among 1,430 women with PPCM (mean age 28.7 ± 5.1 years), 29.5% died over a mean follow-up of 878 days. Delayed diagnosis occurred in 33.8%, and suboptimal GDMT initiation in 57.0%. Mortality was higher in those with delayed diagnosis (34.3% vs 27.0%, p<0.01) and suboptimal GDMT (32.6% vs 20.9%, p<0.001). Complete recovery occurred in 26.9%, while 43.6% had persistent LV dysfunction. Independent mortality predictors were delayed diagnosis (HR 1.3), suboptimal GDMT (HR 1.6), EF <30% (HR 1.6), LV thrombus (HR 2.5), LVIDd ≥60 mm (HR 2.7), atrial fibrillation (HR 4.8), and TAPSE <14 mm (HR 6.8). Conclusion: Delayed diagnosis and suboptimal GDMT initiation are modifiable, independent mortality predictors in PPCM. Early recognition and timely therapy are essential to improve survival. Interventions strengthening provider education, diagnostic capacity, and referral pathways may improve outcomes in Tanzania and similar resource-constrained settings.