Impact of patient characteristics on heart failure and cardiomyopathy onset related to pregnancy from 1997 to 2019. Swedish nationwide register-based study

Abstract

Abstract Background The aetiology of heart failure (HF) in young patients is heterogenic. Cardiomyopathies are common causes in young patients, that often unmask in situations of higher physical demands, as pregnancy or delivery, presenting with HF signs and symptoms. Peripartum cardiomyopathy (PPCM) is one form associated with delivery. However, even other, such as dilated or hypertrophic cardiomyopathy may present during pregnancy. Despite major advances in care, there is still a lack of knowledge about factors that trigger heart failure onset during pregnancy and delivery. Aim To evaluate the association of baseline characteristics for HF and cardiomyopathy (CM) onset related to delivery, and investigate incidence rate for HF and cardiomyopathies related to delivery over time. Method All women 18 to 50 years registered in the National Patient Register (NPR) from 1st January 1997 to 31st December 2019 were included. Time of delivery was obtained from the Swedish Medical Birth Register (MBR), time of death from the Cause of Death Register. Women with HF, CM and peripartum cardiomyopathy (PPCM) were identified from the NPR with international classification codes for disease ICD-10: I50, I42, I43 and 090.3, used for the first time 90 days prior or 180 days after delivery, and other comorbidities. Patients were compared with five controls without HF or CM from the Total Population Register matched by age, year of delivery, and county. Linear regression was used to test trend changes in use of ICD codes. The impact of baseline characteristics for onset av HF, CM and PPCM in patient compared to controls is presented as odds ratio (OR). Body mass index (BMI) was registered at the beginning of pregnancy. Results Between 1997 and 2019 we identified 2 347 723 deliveries, and 694 women with HF, CM or PPCM, median age 33 (29; 37) years and 3 465 controls. Out of those 493 (71%) had HF, 201 (29%) had any CM and 195 (28.1%) had PPCM. Over time the incidence rate of all conditions increased significantly, se Figure 1. Median BMI at the start of pregnancy increased significantly over time in patients with HF from 22 (20;28) to 27 (23;32), beta 0.1323 (p = 0.0216). Compared to controls patients with congenital heart disease OR at 18.32 (10.04-33.41), valve disease OR at 22.65 (8.55-60.03), arrythmia OR at 7.45 (4.06-13.67), hypertension OR at 7.89 (4.26-14.63), diabetes mellitus type II OR at 8.07 (2.63-24.74) and gestational diabetes OR at 3.93 (2.54-6.07) (all p<0.001) to for HF, CM or PPCM onset related to delivery, also BMI >22,5 at the beginning of pregnancy, lower education level and income, se Figure 2. Conclusion Over 22 years we observed a significant increase in the incidence rate of HF and CM related to delivery. BMI already >22,5 was associated with higher risk for HF or any CM onset in relation to delivery.