Long-Term Cardiovascular Outcomes After Pregnancy in Women With Heart Disease

Abstract

Background Women with heart disease are at risk for pregnancy complications, but their long-term cardiovascular outcomes after pregnancy are not known. Methods and Results We examined long-term cardiovascular outcomes after pregnancy in 1014 consecutive women with heart disease and a matched group of 2028 women without heart disease. The primary outcome was a composite of mortality, heart failure, atrial fibrillation, stroke, myocardial infarction, or arrhythmia. Secondary outcomes included cardiac procedures and new hypertension or diabetes mellitus. We compared the rates of these outcomes between women with and without heart disease and adjusted for maternal and pregnancy characteristics. We also determined if pregnancy risk prediction tools (CARPREG [Canadian Cardiac Disease in Pregnancy] and World Health Organization) could stratify long-term risks. At 20-year follow-up, a primary outcome occurred in 33.1% of women with heart disease, compared with 2.1% of women without heart disease. Thirty-one percent of women with heart disease required a cardiac procedure. The primary outcome (adjusted hazard ratio, 19.6; 95% CI, 13.8-29.0; P<0.0001) and new hypertension or diabetes mellitus (adjusted hazard ratio, 1.6; 95% CI, 1.4-2.0; P<0.0001) were more frequent in women with heart disease compared with those without. Pregnancy risk prediction tools further stratified the late cardiovascular risks in women with heart disease, a primary outcome occurring in up to 54% of women in the highest pregnancy risk category. Conclusions Following pregnancy, women with heart disease are at high risk for adverse long-term cardiovascular outcomes. Current pregnancy risk prediction tools can identify women at highest risk for long-term cardiovascular events.

Keywords: cardiovascular; heart disease; long‐term; pregnancy.

Figure 1. Adjusted time‐to‐event curves for primary outcome and hazard ratios.

A, Adjusted cumulative incidence of the primary outcome (all‐cause mortality, heart failure, myocardial infarction, stroke, arrhythmia, or atrial fibrillation) with 95% CIs in the heart disease group and matched comparison group. Numbers at risk were obtained from unadjusted cumulative incidence curves. B, Instantaneous hazard ratio (point estimates and 95% CIs) of primary outcome in heart disease group (comparison group=referent) as a function of follow‐up time.

Figure 2. Adjusted time‐to‐event curves for selected secondary outcomes.

Adjusted cumulative incidence and 95% CIs for selected secondary outcomes (heart failure [A], atrial fibrillation [B], therapeutic cardiac procedures [C], and new hypertension or diabetes mellitus [D]) in heart disease group and matched comparison group. Numbers at risk were obtained from unadjusted cumulative incidence curves.

Figure 3. Pregnancy risk groups: adjusted time‐to‐event curves for primary outcome and hazard ratios.

Adjusted cumulative incidence of primary outcome and 95% CIs as a function of maternal cardiovascular risk during index pregnancy. Incidence rates are separated into low pregnancy risk heart disease group vs intermediate‐to‐high pregnancy risk heart disease group, as defined by the CARPREG (Canadian Cardiac Disease in Pregnancy) risk score (A), and the modified World Health Organization classification system (C). Numbers at risk were obtained from unadjusted cumulative incidence curves. Comparison group denotes matched community comparison group. Instantaneous hazard ratios (point estimates and 95% CIs) for the low (in blue) and intermediate‐to‐high (in red) pregnancy risk groups corresponding to the CARPREG risk score (B) and WHO (D) risk classification are shown (comparison group=referent).

Figure 4. CARPREG (Canadian Cardiac Disease in Pregnancy) II adjusted time‐to‐event curves for primary outcome and hazard ratios.

A, Adjusted cumulative incidence of primary outcome (with 95% CIs) as a function of maternal cardiovascular risk during index pregnancy in the low pregnancy and intermediate‐to‐high (Int‐High) pregnancy risk heart disease groups, as defined by the CARPREG II risk score. Comparison group denotes matched community comparison group. No at risk denotes number at risk from unadjusted cumulative incidence curves. B, Instantaneous hazard ratios (with 95% CIs) of primary outcome (matched community group=referent) as a function of time, in the low (in blue) and intermediate‐to‐high (in red) risk groups corresponding to the CARPREG II risk score.