Predictors and prognostic role of low myocardial mechano-energetic efficiency in chronic inflammatory arthritis

OBJECTIVE: To assess the variables associated with the status of low myocardial mechano-energetic efficiency (MEE) [the ratio between myocardial left ventricular (LV) work and magnitude of myocardial oxygen consumption] and whether low-MEE is a prognosticator of adverse cardiovascular outcome in patients with chronic inflammatory arthritis.METHODS: A total of 432 outpatients with established chronic inflammatory arthritis without overt cardiac disease were recruited from March 2014-March 2016; 216 participants were used as comparison group. Low-MEE status was a priori identified by standard echocardiography at rest as less than 0.32 ml/s per g (5th percentile of MEE calculated in 145 healthy individuals). The pre-specified primary end-point of the study was a composite of cardiovascular death/hospitalization. Follow-up ended September 2019.RESULTS: MEE was significantly lower in chronic inflammatory arthritis patients than controls (0.35 ± 0.11 vs. 0.45 ± 0.10 ml/s per g; P < 0.001). Low-MEE was detected in 164 patients (38%). Independent predictors of low-MEE were older age, higher SBP, diabetes mellitus, LV concentric geometry and lower LV systolic function. During a follow-up of 36 (21-48) months, a primary end-point occurred in 37 patients (8.6%): 22/164 patients with low-MEE (13.4%) and 15/268 (5.6%) without low-MEE (P = 0.004). Low-MEE predicted primary end-points in multivariate Cox regression analysis [heart rate 2.23 (confidence interval 1.13-4.38), P = 0.02] together with older age, lower renal function and higher LV mass.CONCLUSION: Low-MEE is detectable in more than one-third of patients with chronic inflammatory arthritis and is associated with traditional cardiovascular risk factors and abnormalities in LV geometry and systolic function. In these patients low-MEE is a powerful prognosticator of adverse cardiovascular events.