Left atrial appendage 2D-strain assessed by transesophageal echocardiography is associated with thromboembolic risk in patients with atrial fibrillation.

OBJECTIVE: The aim of this study was to determine the relationship of left atrial appendage (LAA) mechanics assessed using 2-dimensional (2D)-strain analysis of the gray scale images obtained during transesophageal echocardiography (TEE) to the conventional LAA functional parameters, CHA2DS2-VASc score, and the presence of spontaneous echo contrast (SEC) and/or LAA thrombus in patients with non-valvular atrial fibrillation (AF). METHODS: The study included 126 patients with AF and 30 controls with a sinus rhythm who were referred for TEE. The global, medial, lateral and apical LAA longitudinal 2D-strain of all patients and the CHA2DS2-VASc score of AF patients were evaluated. RESULTS: The global, medial, lateral, and apical LAA longitudinal 2D-strain results of AF patients were significantly lower than those of the controls and revealed moderate but significant correlations with LAA flow velocity and LAA area change. Patients with a CHA2DS2-VASc score of 0 or 1 had the highest LAA 2D-strain values and the results revealed that the LAAemptying velocity and LAA lateral and medial 2D-strain values were independent correlates of CHA2DS2-VASc score. SEC was detected in 84 patients, of whom, 42 had dense SEC and 27 had thrombus in the LAA. Multivariate analysis indicated that LAA emptying velocity, LAA area change, and LAA medial 2D-strain were independently associated with the presence of dense SEC/thrombus. In ROC analysis, cut-off values for global, medial, apical, and lateral 2D-strain for the presence of dense SEC/ thrombus were 6.0% p=0.011), 8.0% (p=0.032), 6.0% (p=0.033), and 5.4% (p=0.004), respectively. CONCLUSION: Global and regional LAA mechanics were significantly related to conventional LAA functional parameters and to the presence of LAA-dense SEC/thrombus in patients with AF and may be useful as complementary data for estimating future thromboembolism.

Elevated levels of vitamin B12 in chronic stable heart failure: a marker for subclinical liver damage and impaired prognosis.

BACKGROUND: Elevated vitamin B12 is a sign for liver damage, but its significance in chronic stable heart failure (HF) is less known. The present study investigated the clinical correlates and prognostic significance of vitamin B12 levels in stable systolic HF. METHODS: A total of 129 consecutive patients with HF and 50 control subjects were enrolled. Data regarding demographics, clinical signs, therapeutic and conventional echocardiographic measurements were recorded for all patients. Right-sided HF was defined as the presence of at least one of the typical symptoms (ankle swelling) or specific signs (jugular venous distention or abdominojugular reflux) of right HF. Cox proportional hazards regression analyses were performed to determine the independent prognostic determinants of mortality. RESULTS: Baseline B12 levels in HF patients (n=129) with and without right sided HF were significantly higher compared to healthy controls (n=50): Median 311 pg/mL and 235 pg/mL vs 198 pg/mL, respectively (P=0.005). Folic acid levels were similar between the study groups. Age, ejection fraction, left atrial size, estimated glomerular filtration rate, and direct and indirect bilirubin levels were significantly correlated to serum B12 level in univariate analysis. In multivariate analysis, independent correlates of B12 were direct bilirubin (R=0.51, P<0.001) and age (R=0.19, P=0.028). Patients with HF were followed-up for a median period of 32 months. Median B12 levels were significantly higher in patients who subsequently died (n=35) compared to survivors, but folic acid was not different between the two groups. ROC analysis showed that B12 values ≥270 pg/mL had 80% sensitivity and 58% specificity for predicting all-cause mortality (area under the curve=0.672, 95% CI=0.562-0.781; P=0.003). However, in Cox regression analysis, only left atrial diameter, level of direct bilirubin, and the presence of abdominojugular reflux were independent predictors of death. CONCLUSION: Increased B12 in stable HF patients is associated with increased direct bilirubin due to right HF, indicating a cardiohepatic syndrome, but neither B12 nor folic acid are independently associated with mortality.

Improvement in left ventricular intrinsic dyssynchrony with cardiac resynchronization therapy.

OBJECTIVE: Cardiac resynchronization therapy (CRT) has been shown to induce a structural and electrical remodeling; the data on whether left ventricle (LV) reverse remodeling is associated with restitution of intrinsic contraction pattern are unknown. In this study, we investigated the presence of improvement in left ventricular intrinsic dyssynchrony in patients with CRT. METHODS: A total of 45 CRT recipients were prospectively studied. Dyssynchrony indexes including interventricular mechanical delay (IVMD) and tissue Doppler velocity opposing-wall delay (OWD) as well as QRS duration on 12-lead surface electrocardiogram were recorded before CRT device implantation. After 1 year, patients with chronic biventricular pacing were reprogramed to VVI 40 to allow the resumption of native conduction and contraction pattern. After 4-6 h of intrinsic rhythm, QRS duration and all echocardiographic measurements were recorded. Dyssynchrony was defined as IVMD >40 ms and OWD >65 ms. CRT response was defined by a ≥15% reduction in left ventricular end-systolic volume (LVESV) at a 12-month follow-up. RESULTS: Thirty-two patients (71%) showed response to CRT. The native QRS duration reduced significantly from 150±12 ms to 138±14 ms (p<0.001), and dyssynchrony indexes showed a significant improvement only in responders. The mean OWD reduced from 86±37 ms to 50±29 ms (p<0.001), and the mean IVMD decreased from 55±22 ms to 28±22 ms (p<0.001) in responders. The reduction in LVESV was significantly correlated with ΔOWD (r=0.47, p=0.001), ΔIVMD (r=0.45, p=0.001), and ΔQRS (r=0.34, p=0.022). CONCLUSION: Chronic CRT significantly improves LV native contraction pattern and causes reverse remodeling in dyssynchrony.

What is the lowest value of left ventricular baseline ejection fraction that predicts response to cardiac resynchronization therapy?

BACKGROUND: Cardiac resynchronization therapy (CRT) is an effective treatment option for patients with refractory heart failure. However, many patients do not respond to therapy. Although it has been thought that there was no relation between response to CRT and baseline ejection fraction (EF), the response rate of patients with different baseline LVEF to CRT has not been evaluated in severe left ventricular systolic dysfunction. We aimed to investigate any difference in response to CRT between the severe heart failure patients with different baseline LVEF. MATERIAL AND METHODS: In this study, 141 consecutive patients (mean age 59±13 years; 89 men) with severe heart failure and complete LBBB were included. Patients were divided into 3 groups according to their baseline LVEF: 5-15%, Group 1; 15-25%, Group 2, and 25-35%, Group 3. NYHA functional class, LVEF, LV volumes, and diameters were assessed at baseline and after 6 months of CRT. A response to CRT was defined as a decrease in LVSVi (left ventricular end-systolic volume index) ≥10% on echocardiography at 6 months. RESULTS: After 6 months, a significant increase of EF and a significant decrease of LVESVi and LVEDVi after 6 months of CRT were observed in all groups. Although the magnitude of improvement in EF was biggest in the first group, the percentage of decrease in LVESVi and LVEDVi was similar between the groups. The improvement in NYHA functional class was similar in all EF subgroups. At 6-month follow-up, 100 (71%) patients showed a reduction of >10% in LVESVi (mean reduction: -15.5±26.1 ml/m^2) and were therefore classified as responders to CRT. Response rate to CRT was similar in all groups. It was 67%, 75%, and 70% in Group 1, 2, and 3, respectively, at 6-month follow-up (p>0.05). There was no statistically significant relation between the response rate to CRT and baseline LVEF, showing that the CRT has beneficial effects even in patients with very low LVEF. CONCLUSIONS: It seems there is no lower limit for baseline LVEF to predict non-response to CRT in eligible patients according to current guidelines.