Subclinical hypothyroidism and its relationship with therapy failure in patients underwent cardiac resynchronization therapy.

OBJECTIVE: Cardiac resynchronization therapy (CRT) is used in patients with heart failure (HF), an important problem in cardiology practice, with reduced left ventricular systolic dysfunctions and left ventricular dyssynchrony to improve morbidity and mortality. Thyroid diseases have undeniable effects on cardiac functions. So, we aimed to evaluate the effect of subclinical hypothyroidism on CRT response in HF patients in this study. PATIENTS AND METHODS: After the exclusion, 386 consecutive patients who received first-time CRT-defibrillator (CRT-D) or CRT-pacemaker (CRT-P) were retrospectively included. Known overt hypothyroidism or hyperthyroidism patients were excluded. The response of CRT was defined as a relative increase (≥15%) or absolute increase (≥10%) in left ventricular ejection fraction (LVEF) from implantation to one-year after follow-up. RESULTS: Diabetes mellitus, atrial fibrillation and coronary artery disease ratios were similar between responder vs. non-responder groups. Thyroid stimulating hormone (TSH) levels were higher (p <0.005) in non-responder group. Responder group had higher baseline LVEF (p <0.001), and follow-up LVEF (p <0.001) and longer baseline QRS interval (p =0.004), but similar post-implant QRS interval duration (p >0.005) with non-responder group. Baseline QRS interval (p =0.002), baseline LVEF (p <0.001) and the presence of subclinical hypothyroidism (SCH) (p =0.001) were independent predictors of CRT response. Adding SCH as a risk factor to our baseline risk modelling has an independent prognostic impact to predict non-responder patients (p =0.01). CONCLUSIONS: Presence of the SCH may be an important predictor of non-response in patients undergoing CRT. Evaluating the risk factors associated with non-response to CRT may be logical in identifying patients who obtain maximum benefit from CRT treatment.

Correlation of the coronary severity scores and mean platelet volume in diabetes mellitus.

INTRODUCTION: It is known that mean platelet volume (MPV) increases during acute coronary syndrome. However, there are conflicting data about the importance of MPV in patients with stable coronary artery disease (CAD). This study aimed to assess relationship between MVP and the severity of coronary atherosclerosis in patients with diabetes mellitus (DM), stable CAD and normal left ventricular ejection fractions. METHODS: Thirty-three DM and 46 nonDM patients with stable CAD diagnosed by selective coronary angiography were included in the study. All angiographic variables pertinent to Gensini score (GS) and Syntax score (SS) calculation were computed by two experienced interventional cardiologists. All patients underwent echocardiographic examination. MPV and other biochemical markers were measured on admission. RESULTS: All patients were evaluated and it was found that both scoring systems are correlated with MPV (GS: r = 0.373, p < 0.001; SS: r = 0.385, p < 0.001). DM and nonDM groups were severally evaluated, it was found that the correlation between MPV and GS and SS increased in DM patients (GS: r = 0.638, p < 0.001; SS: r = 0.624, p < 0.001); however, no differences were identified in nonDM patients (GS: r = 0.124, p = 0.410; SS: r = 0.124, p = 0.411). CONCLUSION: It is thought that high MPV levels may be an effective marker in determining the severity of CAD in patients with DM. And the high MPV level may be related with CAD pathophysiology in DM patients.