Anxiety sensitivity in heart failure with preserved ejection fraction: Bias in dyspnea ratings and respiratory exercise response

BACKGROUND Anxiety sensitivity, the fear of anxiety symptoms, is linked to elevated symptom reports in health and illness. Dyspnea on exertion, a dominant complaint in heart failure with preserved ejection fraction (HFpEF), could be affected by this personality characteristic. We examined whether patients with HFpEF and high anxiety sensitivity provide elevated dyspnea reports in global measures or in response to cardiopulmonary exercise testing under regular or pharmacological challenge conditions. METHOD Fifty-three patients (37 women, mean age 71.4 years) with HFpEF completed the Anxiety Sensitivity Index (ASI), Dyspnoea-12 questionnaire, and modified Medical Research Council dyspnea rating (mMRC), and pulmonary function testing. They also performed six-minute constant-load cycling at 20W and incremental cycling to exhaustion, with placebo or sublingual nitroglycerin in a single-blind, cross-over design. Ratings of perceived breathlessness and its unpleasantness, and ventilation and arterial blood gas measurements, were completed at rest, during the final minute of constant-load cycling, and immediately after incremental cycling. RESULTS ASI scores predicted Dyspnoea-12, but not mMRC scores. Across rest and exercise, PaCO2 and ventilatory efficiency was lower, and minute ventilation, dead space, and breathlessness ratings were higher, under nitroglycerin challenge. Under this condition, patients with higher ASI also reported more breathlessness across the exercise protocol, required greater E to eliminate CO2 (E/ CO2), and had lower PaCO2 at pre-exercise while waiting for the nitroglycerin to take effect. CONCLUSION Overreporting of dyspnea and mild hyperventilation need to be considered when testing patients with HFpEF that are high in anxiety sensitivity in unusual medical situations that elicit symptoms.