Are we missing hypertrophic cardiomyopathy in pregnancy? Experience of a tertiary care hospital

Hypertrophic Cardiomyopathy and Pregnancy: A Retrospective Analysis From a Tertiary Care Hospital

Pregnancy in women with hypertrophic cardiomyopathy is not well described. In this retrospective study, we analyzed data on pregnant women with hypertrophic cardiomyopathy who were under follow-up care in the cardiology department of a tertiary care hospital. We reviewed data on all women registered in the hypertrophic cardiomyopathy cohort and those who attended the cardio-obstetric clinic and delivered between January 2010 and June 2019. From these 2 groups, we identified 7 pregnant women with hypertrophic cardiomyopathy who delivered during this period. These 7 women (mean [SD] age, 25 [3.3] years) had a total of 15 pregnancies (range per woman,1-4). This was a high-risk cohort, as 7 (46.7%) pregnancies were in the modified World Health Organization class III. The mean (SD) left ventricular wall thickness was 19.71 (2.56) mm in all pregnancies. Two of the 7 women with left ventricular outflow tract obstruction developed severe symptoms in the third trimester; these improved soon after delivery. Eight pregnancies without obstruction were well tolerated. Two pregnancies occurred after successful alcohol septal ablation. Both remained asymptomatic throughout pregnancy. All women tolerated labor well. Adverse maternal outcomes, including death, were not seen in any patient. All women who became symptomatic during pregnancy had relief of symptoms after delivery. Most women remained asymptomatic or had mild symptoms during pregnancy. Of the women with left ventricular outflow tract obstruction, 28.6% had severe symptoms that improved after delivery. Pregnancy was well tolerated after successful alcohol septal ablation.

Cardiomyopathy and pregnancy

Cardiomyopathy is a group of disorders in which the heart muscle is structurally and functionally abnormal in the absence of other diseases that could cause observed myocardial abnormality. The most common cardiomyopathies are hypertrophic and dilated cardiomyopathy. Rare types are arrhythmogenic right ventricular, restrictive, Takotsubo and left ventricular non-compaction cardiomyopathies. This review of cardiomyopathies in pregnancy shows that peripartum cardiomyopathy is the most common cardiomyopathy in pregnancy. Peripartum cardiomyopathy develops most frequently in the month before or after partum, whereas dilated cardiomyopathy often is known already or develops in the second trimester. Mortality in peripartum cardiomyopathy varies from <2% to 50%. Few reports on dilated cardiomyopathy and pregnancy exist, with only a limited number of patients. Ventricular arrhythmias, heart failure, stroke and death are found in 39%-60% of high-risk patients. However, patients with modest left ventricular dysfunction and good functional class tolerated pregnancy well. Previous studies on >700 pregnancies in 500 women with hypertrophic cardiomyopathy showed that prognosis was generally good, even though three deaths were reported in high-risk patients. Complications include different types of supraventricular and ventricular arrhythmias, heart failure and ischaemic stroke. Recent studies on 200 pregnancies in 100 women with arrhythmogenic right ventricular cardiomyopathy have reported symptoms, including heart failure in 18%-33% of pregnancies. Ventricular tachycardia was found in 0%-33% of patients and syncope in one patient. Information on rare cardiomyopathies is sparse and only presented in case reports. Close monitoring by multidisciplinary teams in referral centres that counsel patients before conception and follow them throughout gestation is recommended.

Brain natriuretic peptide in pregnant women with heart disease

Background

Plasma brain natriuretic peptide levels were prospectively studied in pregnant women with heart disease.

Methods

Fifty pregnant women with heart disease and 25 controls were evaluated at 24 weeks or under, 30-32 weeks, 34 weeks or more of gestation, and 6 weeks postpartum. Adverse maternal cardiac events were hospitalization for worsening heart failure, stroke, and death.

Results

Thirty-eight (76%) women had rheumatic heart disease. Plasma brain natriuretic peptide levels were (in cases and controls) 118.3 ± 46.5 pg/ml and 66.3 ± 15.9 pg/ml (at 24 weeks or under), 124.8 ± 30.4 pg/ml and 68.4 ± 16.5 pg/ml (30-32 weeks), 135.8 ± 34.9 pg/ml and 68.6 ± 15.6 pg/ml (34 weeks or more), and 110.1 ± 21.9 pg/ml and 65.0 ± 16.1 pg/ml (6 weeks postpartum) (p = .0001). Eighteen women had adverse events. Of these, only 1 had a level less than 100 pg/ml, 12 were between 100 and 200 pg/ml, and 5 more than 200 pg/ml.

Conclusions

Plasma brain natriuretic peptide levels were higher in women with heart disease at all periods of gestation as well as six weeks postpartum. No woman with a plasma brain natriuretic peptide levels of 98 pg/ml or less had an adverse event.