Left Ventricular Diastolic and Systolic Functions in Patients with Hypothyroidism.

Background and objectives: Long standing hypothyroidism may impair myocardial relaxation, but its effect on systolic myocardial function is still controversial. The aim of this study was to investigate left ventricular (LV) systolic and diastolic function in patients with hypothyroidism. Materials and Methods: This study included 81 (age 42 ± 13 years, 92% female) patients with hypothyroidism, and 22 age and gender matched controls. All subjects underwent a detailed clinical examination followed by a complete biochemical blood analysis including thyroid function assessment and anthropometric parameters measurements. LV function was assessed by 2-dimensional, M-mode and Tissue-Doppler Doppler echocardiographic examination performed in the same day. Results: Patients had lower waist/hip ratio (p< 0.001), higher urea level (p = 0.002), and lower white blood cells (p = 0.011), compared with controls. All other clinical, biochemical, and anthropometric data did not differ between the two groups. Patients had impaired LV diastolic function (lower E wave [p< 0.001], higher A wave [p = 0.028], lower E/A ratio [p< 0.001], longer E wave deceleration time [p = 0.01], and higher E/e' ratio [p< 0.001]), compared with controls. Although LV global systolic function did not differ between groups, LV longitudinal systolic function was compromised in patients (lateral mitral annular plane systolic excursion-MAPSE [p = 0.005], as were lateral and septal s' [p< 0.001 for both]). Conclusions: In patients with hypothyroidism, in addition to compromised LV diastolic function, LV longitudinal systolic function is also impaired compared to healthy subjects of the same age and gender. These findings suggest significant subendocardial function impairment, reflecting potentially micro-circulation disease that requires optimum management.

Left ventricular markers of global dyssynchrony predict limited exercise capacity in heart failure, but not in patients with preserved ejection fraction.

BACKGROUND: The aim of this study was to prospectively examine echocardiographic parameters that correlate and predict functional capacity assessed by 6 min walk test (6-MWT) in patients with heart failure (HF), irrespective of ejection fraction (EF). METHODS: In 147 HF patients (mean age 61 ± 11 years, 50.3% male), a 6-MWT and an echo-Doppler study were performed in the same day. Global LV dyssynchrony was indirectly assessed by total isovolumic time - t-IVT [in s/min; calculated as: 60 - (total ejection time + total filling time)], and Tei index (t-IVT/ejection time). Patients were divided into two groups based on the 6-MWT distance (Group I: ≤ 300 m and Group II: >300 m), and also in two groups according to EF (Group A: LVEF ≥ 45% and Group B: LVEF < 45%). RESULTS: In the cohort of patients as a whole, the 6-MWT correlated with t-IVT (r = -0.49, p < 0.001) and Tei index (r = -0.43, p < 0.001) but not with any of the other clinical or echocardiographic parameters. Group I had lower hemoglobin level (p = 0.02), lower EF (p = 0.003), larger left atrium (p = 0.02), thicker interventricular septum (p = 0.02), lower A wave (p = 0.01) and lateral wall late diastolic myocardial velocity a' (p = 0.047), longer isovolumic relaxation time (r = 0.003) and longer t-IVT (p = 0.03), compared with Group II. In the patients cohort as a whole, only t-IVT ratio [1.257 (1.071-1.476), p = 0.005], LV EF [0.947 (0.903-0.993), p = 0.02], and E/A ratio [0.553 (0.315-0.972), p = 0.04] independently predicted poor 6-MWT performance (<300 m) in multivariate analysis. None of the echocardiographic measurements predicted exercise tolerance in HFpEF. CONCLUSION: In patients with HF, the limited exercise capacity, assessed by 6-MWT, is related mostly to severity of global LV dyssynchrony, more than EF or raised filling pressures. The lack of exercise predictors in HFpEF reflects its multifactorial pathophysiology.

Diabetes Is the Strongest Predictor of Limited Exercise Capacity in Chronic Heart Failure and Preserved Ejection Fraction (HFpEF).

Background and Aim: Type 2 diabetes mellitus (T2DM) is a known risk factor in patients with heart failure (HF), but its impact on phenotypic presentations remains unclear. This study aimed to prospectively examine the relationship between T2DM and functional exercise capacity, assessed by the 6-min walk test (6-MWT) in chronic HF. Methods: We studied 344 chronic patients with HF (mean age 61 ± 10 years, 54% female) in whom clinical, biochemical, and anthropometric data were available and all patients underwent an echo-Doppler study and a 6-MWT on the same day. The 6-MWT distance divided the cohort into; Group I: those who managed ≤ 300 m and Group II: those who managed >300 m. Additionally, left ventricular (LV) ejection fraction (EF), estimated using the modified Simpson's method, classified patients into HF with preserved EF (HFpEF) and HF with reduced EF (HFrEF). Results: The results showed that 111/344 (32%) patients had T2DM, who had a higher prevalence of arterial hypertension (p = 0.004), higher waist/hips ratio (p = 0.041), higher creatinine (p = 0.008) and urea (p = 0.003), lower hemoglobin (p = 0.001), and they achieved shorter 6-MWT distance (p < 0.001) compared with those with no T2DM. Patients with limited exercise (<300 m) had higher prevalence of T2DM (p < 0.001), arterial hypertension (p = 0.004), and atrial fibrillation (p = 0.001), higher waist/hips ratio (p = 0.041), higher glucose level (p < 0.001), lower hemoglobin (p < 0.001), larger left atrium (LA) (p = 0.002), lower lateral mitral annular plane systolic excursion (MAPSE) (p = 0.032), septal MAPSE (p < 0.001), and tricuspid annular plane systolic excursion (TAPSE) (p < 0.001), compared with those performing >300 m. In the cohort as a whole, multivariate analysis, T2DM (p < 0.001), low hemoglobin (p = 0.008), atrial fibrillation (p = 0.014), and reduced septal MAPSE (p = 0.021) independently predicted the limited 6-MWT distance.In patients with HFpEF, diabetes [6.083 (2.613-14.160), p < 0.001], atrial fibrillation [6.092 (1.769-20.979), p = 0.002], and septal MAPSE [0.063 (0.027-0.184), p = 0.002], independently predicted the reduced 6-MWT, whereas hemoglobin [0.786 (0.624-0.998), p = 0.049] and TAPSE [0.462 (0.214-0.988), p = 0.041] predicted it in patients with HFrEF. Conclusion: Predictors of exercise intolerance in patients with chronic HF differ according to LV systolic function, demonstrated as EF. T2DM seems the most powerful predictor of limited exercise capacity in patients with HFpEF.

Gender related predictors of limited exercise capacity in heart failure.

AIM: The aim of this study was to investigate the impact of gender on the prediction of limited exercise capacity in heart failure (HF) patients assessed by 6 minute walk test (6-MWT). METHODS: In 147 HF patients (mean age 61 ± 11 years, 50.3% male), a 6-MWT and a Doppler echocardiographic study were performed in the same day. Conventional cardiac measurements were obtained and global LV dyssynchrony was indirectly assessed using total isovolumic time - t-IVT [in s/min; calculated as: 60 - (total ejection time - total filling time)] and Tei index (t-IVT/ejection time). Patients were divided into two groups according to gender, which were again divided into two subgroups based on the 6-MWT distance (Group I: ≤ 300 m, and Group II: > 300 m). RESULTS: Female patients were younger (p = 0.02), and had higher left ventricular (LV) ejection fraction - EF (p = 0.007) but with similar 6-MWT distance to male patients (p = 68). Group I male patients had lower hemoglobin level (p = 0.02) and lower EF (p = 0.03), compared with Group II, but none of the clinical or echocardiographic variables differed between groups in female patients. In multivariate analysis, only t-IVT [0.699 (0.552-0.886), p = 0.003], and LV EF [0.908 (0.835-0.987), p = 0.02] in males, and NYHA functional class [4.439 (2.213-16.24), p = 0.02] in females independently predicted poor 6-MWT distance (< 300 m). CONCLUSION: Despite similar limited exercise capacity, gender determines the pattern of underlying cardiac disturbances; ventricular dysfunction in males and subjective NYHA class in female heart failure patients.