The effect of parity on exercise physiology in women with heart failure with preserved ejection fraction

Women are overrepresented amongst patients with heart failure with preserved ejection fraction (HFpEF); however, the underpinning mechanism for this asymmetric distribution is unclear. Pregnancy represents a potential gender-specific risk factor for HFpEF. It leads to significant physiological adaption, and increasing parity has been associated with some cardiovascular risk. We sought to examine the relationship between prior parity with the rest and exercise haemodynamic and echocardiographic profile of women with HFpEF.

Patients referred for assessment of exertional dyspnoea and confirmed to have a haemodynamic and clinical profile consistent with HFpEF were included. Detailed evaluation consisted of rest and exercise right heart catheterization and echocardiography. A socio-economic and obstetric history was also documented. Fifty-eight women were assessed and categorized as having either 0-2 births or ≥3 births, dividing the cohort equally. Women with ≥3 births achieved a lower symptom-limited workload than those with 0-2 births [38 (24-51) vs. 46 (31-68) W, P = 0.04]. Women with ≥3 births had a greater rise in pulmonary capillary wedge pressure indexed to workload with exercise [0.5 (0.3-0.8) vs. 0.3 (0.2-0.5) mmHg/W, P = 0.03], paralleled by a greater rise in right atrial pressure [10 (8-12) vs. 7 (3-11), P = 0.01]. Pulmonary vascular resistance was also higher in women with ≥3 births [1.9 (1.6-2.4) vs. 1.6 (1.4-1.9) mmHg/L/min rest, P = 0.046, and 1.9 (2.4-2.4) vs. 1.4 (1-1.8) mmHg/L/min exercise, P = 0.024]. Left ventricular ejection fraction was lower at rest [60 (57-61) vs. 63 (60-66), P = 0.008] and during exercise [65 (62-67) vs. 68 (66-70), P = 0.038] in women with higher parity.

Higher parity is associated with greater impairments in multiple physiologic parameters of HFpEF severity in women, including diastolic reserve, pulmonary vascular resistance, and systolic dysfunction.