Almeida-Morais, LAbreu, AOliveira, MMSilva Cunha, PRodrigues, IPortugal, GRio, PSoares, RMMota Carmo, MCruz Ferreira, R2018-12-192018-12-192018-02Rev Port Cardiol. 2018 Feb;37(2):105-113.http://hdl.handle.net/10400.17/3138INTRODUCTION: Response to cardiac resynchronization therapy (CRT) can currently be assessed by clinical or echocardiographic criteria, and there is no strong evidence supporting the use of one rather than the other. Reductions in B-type natriuretic peptide (BNP) and C-reactive protein (CRP) have been shown to be associated with CRT response. This study aims to assess variation in BNP and CRP six months after CRT and to correlate this variation with criteria of functional and echocardiographic response. METHODS: Patients undergoing CRT were prospectively enrolled between 2011 and 2014. CRT response was defined by echocardiography (15% reduction in left ventricular end-systolic volume) and by cardiopulmonary exercise testing (10% increase in peak oxygen consumption) from baseline to six months after device implantation. RESULTS: A total of 115 patients were enrolled (68.7% male, mean age 68.6±10.5 years). Echocardiographic response was seen in 51.4% and 59.2% were functional responders. There was no statistical correlation between the two. Functional response was associated with a significantly greater reduction in BNP (-167.6±264.1 vs. -24.9±269.4 pg/ml; p=0.044) and CRP levels (-1.6±4.4 vs. 2.4±9.9 mg/l; p=0.04). Nonetheless, a non-significant reduction in BNP and CRP was observed in echocardiographic responders (BNP -144.7±260.2 vs. -66.1±538.2 pg/ml and CRP -7.1±24.3 vs. 0.8±10.3 mg/l; p>0.05). CONCLUSION: An increase in exercise capacity after CRT implantation is associated with improvement in myocardial remodeling and inflammatory biomarkers. This finding highlights the importance of improvement in functional capacity after CRT implantation, not commonly considered a criterion of CRT response.engHSM CARBiomarkers/bloodC-Reactive Protein/analysisCardiac Resynchronization TherapyEchocardiographyHeart Failure/bloodHeart Failure/diagnostic imagingHeart Failure/physiopathologyHeart Failure/therapyInflammation/bloodNatriuretic Peptide, Brain/bloodProspective StudiesVentricular Remodelingjournal article10.1016/j.repc.2017.06.017