Early excess mortality and hospitalisation after pregnancy-associated heart failure: a nationwide registry study from 1997 to 2022
T Toska, E Thunstrom, M Fu, C Backstrom, C BasicAbstract
Background
Heart failure (HF) and cardiomyopathy during pregnancy or the postpartum period are uncommon but potentially life-threatening conditions. Contemporary real-world data on medication use, treatment duration and tapering, as well as early risks of mortality and hospitalisation, remain limited.
Aim
To investigate clinical characteristics, treatment patterns, and 3-year outcomes in women with pregnancy-associated HF or cardiomyopathy compared with matched controls.
Method
In this nationwide registry-based cohort study, women aged 18-50 years in the National Patient Register (1997–2022) were linked to the National Birth, Death, and Prescription Registers. Women with first-time HF or cardiomyopathy occurring 90 days before to 180 days after delivery were identified using ICD-10 codes I50, I42, I43, and O90.3. Each case was matched with five controls without HF or cardiomyopathy from the Total Population Register, based on age and delivery date.
Results
Among 2,347,723 deliveries, 451 cases and 2,255 controls were included. Mean age was similar between groups (33.1 ± 5.6 vs 33.0 ± 5.6 years, p=0.82). Cases had higher BMI (33.1 ± 6.8 vs 30.4 ± 5.3 kg/m², p<0.0001) and a higher prevalence of hypertension (5.1% vs 0.3%, p<0.0001), atrial fibrillation (0.9% vs 0.1%, p=0.0010), and psychiatric disorders (16.2% vs 11.1%, p=0.0023). Within 3 months postpartum, cases more frequently received beta-blockers (18.8% vs 0.9%), ACE inhibitors/ARBs/ARNI (19.3% vs 0.4%), MRAs (7.1% vs 0%), SGLT2 inhibitors (0.4% vs 0%), diuretics (11.3% vs 0.1%), and bromocriptine (4.2% vs 0.1%) (all p≤0.028). Beta-blocker treatment duration was longer in cases (376 vs 72 days, p=0.0002), whereas no difference was observed for ACE/ARB/ARNI. Cases had also more often beta-blockers (first tapered: 8.6% vs 0.9%; last tapered: 14.2% vs 0.8%), ACE/ARB/ARNI (12.2% vs 0.3%; 13.3% vs 0.4%), MRAs (2.4% vs 0.0%; 1.8% vs 0.0%), diuretics (7.8% vs 0.1%; 3.8% vs 0.1%), as the first and last drug tapered (all p<0.0001). Within 3 years, all-cause mortality occurred in 1.3% of cases (event rate 4.5 per 1,000 person-years) compared with 0.1% of controls (0.4 per 1,000 person-years), corresponding to a hazard ratio (HR) of 10.07 (95% CI 2.52–40.26; p=0.0011). Cardiovascular hospitalisation occurred in 34.4% of cases (165.7 per 1,000 person-years) vs. 0.7% of controls (2.4 per 1,000 person-years), with HR 59.77 (95% CI 35.71–100.04; p<0.0001). Overall hospitalisation occurred in 42.8% of cases (225.6 per 1,000 person-years) compared with 8.2% of controls (28.7 per 1,000 person-years), HR 7.06 (95% CI 5.76 - 8.64; p<0.0001).
Conclusion
Pregnancy-associated heart failure and cardiomyopathy are linked to markedly elevated early risks of mortality and cardiovascular hospitalization, as well as a substantially increased healthcare burden. These findings underscore the need for structured postpartum follow-up and improved care pathways for this high-risk population.