Independent association between uric acid levels and myocardial mechano-energetic efficiency as assessed by echocardiography

Objective: In the last decades several studies have investigated the relationship between serum uric acid (SUA) levels and cardiovascular disease and heart failure. Low myocardial mechano-energetic efficiency (MEE), estimated as stroke volume/heart rate ratio per g of left ventricular (LV) mass (LVM) is an independent predictor of cardiovascular (CV) events and heart failure. Design and method: Aim of the study was to evaluate the relationship between SUA and myocardial mechano-energetic efficiency index (MEEi) in 694 consecutive uncomplicated patients attending the outpatient at an ESH Excellence Centre in Italy. Methods BP values were measured by the physician with an automated oscillometric device, after 5 minutes of rest. All patients underwent transthoracic echocardiography, and standard indices of systolic function were calculated. In all patients myocardial mechanoenergetic efficiency (MEE) was calculated as stroke volume/heart rate and indexed to LV mass (MEEi = MEE/LVM) (de Simone et al, 2016). Results: Results Mean age was 57±13 yrs, 52% female, 21 % obese, 10 % diabetics, 69 % with a previous diagnosis of hypertension (77 % treated). MEEi was lower in males (0.42±0.14 vs 0.49±0.16, p<0.001), and in patients with diabetes (0.38±0.11 vs 0.47±0.16, p<0.001). At multivariate analysis the variables independently correlated with MEEI were male sex, systolic blood pressure, presence of obesity, plasma glucose levels, and serum uric acid, but not age and eGFR (CKD EPI). At receiver operating curves (ROC) analysis the optimal cutoff of uric acid for the prediction on reduced MEEI was 5.4 mg/dl (AUC 0.611. 95 CI 0.574-0.648). Conclusions: Conclusions In a large sample of uncomplicated patients attending the outpatient clinic at an ESH Excellence Centre in Italy uric acid is an independent predictor of myocardial mechanoenergetic efficiency. In this population the optimal cutoff of uric acid for reduced MEEI is 5.4 mg/dl. These findings may contribute to the explanation of the greater risk of heart failure in patients with increased uric acid levels.