Determinants of exercise intolerance symptoms considered non-specific for heart failure in patients with stage A and B: role of the left atrium in the transition phase to overt heart failure

To assess to what extent left atrial (LA) structure and function are associated with non-specific heart failure symptoms, so that patients were classified as HF stage A and B. Mechanisms underlying the transition to overt HF in patients with stage A and B HF are unclear. Consecutive outpatients undergoing echocardiography and clinical evaluation and classified as HF stage A and B with preserved left ventricular ejection fraction (LVEF) were included. The association between LA measures [volume (LAVi), peak longitudinal-(PALS), contraction-(PACS) and conduit-strain] and non-specific HF symptoms was assessed using adjusted logistic regression analyses. The incremental value of atrial myopathy in symptoms prediction on top of clinical or echocardiographic confounders was assessed through ROC curves analyses. The cohort comprehended 185 patients (63 ± 16 years, 47% women) of whom 133 (72%) were asymptomatic, and 52 (28%) reported non-specific HF symptoms. After adjustment for clinical and echocardiographic confounders for HF symptoms, LAVi, PALS and PACS were associated with symptoms (p < 0.05). Among echocardiographic variables, only LA parameters were significantly associated with symptoms on top of clinical confounders (for LAVi OR [95% CI] 1.56 [1.21-2.00], p < 0.0001; for PALS 1.45 (1.10-1.91), p = 0.0009; for PACS 2.10 [1.33-3.30], p = 0.002). After adjustment for age, hypertension and COPD or E/E', LV mass-i and mitral ERO, atrial myopathy added predictive value for symptoms presence compared to the clinical variables or echocardiographic parameters described (AUC increase 0.80 to 0.88, p = 0.004, and 0.79 to 0.84, p = 0.06, respectively). In patients with HF stages A-B and preserved LVEF, measures of LA structure and function were associated with non-specific HF symptoms. A comprehensive LA remodeling evaluation may help clinicians in the appropriate identification of overt HF.