Subclinical atrial fibrillation frequency and associated parameters in patients with cardiac resynchronization therapy

AIM

The presence of subclinical atrial fibrillation (SCAF) is relevant to issues such as the risk of stroke and the necessity of anticoagulant use in patients with cardiac resynchronization therapy (CRT). Our study aimed to investigate SCAF frequency and associated parameters in patients with CRT.

METHODS

One hundred ninety-one patients with CRT (77 females, 114 males, mean age 65.9 ± 9.8) were included in the study. Atrial high-rate episodes detected by the device, atrial electrode impedance, P-wave sense amplitude, and atrial lead threshold values were measured during pacemaker controls. SCAF was defined as asymptomatic atrial high-rate episodes (AHRE) longer than 6 min and shorter than 24 h. Patients were divided into two groups as with and without SCAF.

RESULTS

SCAF was detected in 44 (23.2%) of 191 patients with CRT. Age, sex, weight, aortic end-systolic diameter, left atrium (LA) diameter, left bundle branch block morphology, CHA₂DS₂-VASc score, and right atrium thresholds were associated with SCAF. In multivariate regression analysis, CHA₂DS₂-VASc score, LA diameter, and atrial threshold values were found to be independent predictors of SCAF occurrence. According to this analysis, every 1 point increase in CHA₂DS₂-VASc score, every 1 mm increase in LA diameter, and every 0.1 V increase in atrial threshold increased the risk of SCAF by 32.5, 59.6, and 14.6%, respectively. In the ROC analysis, the area under the curve (AUC) was 0.870, 0.638, and 0,652 for LA diameter, CHA2DS2-VASc score, and atrial lead threshold, respectively (p < 0.05, for all). The cut-off values were 34 mm, 3, and 0.6 V for LA diameter, CHA2DS2-VASc score, and atrial lead threshold, respectively.

CONCLUSION

Patients with CRT have significantly higher frequency of SCAF than the normal population. CHA₂DS₂-VASc score, LA diameter, and atrial threshold values were considered to be useful and easily applicable parameters in identifying the patients to develop SCAF.

Fibrosis Marker Soluble ST2 Predicts Atrial Fibrillation Recurrence after Cryoballoon Catheter Ablation of Nonvalvular Paroxysmal Atrial Fibrillation

Background and Objectives

We aimed to investigate the relationship between the recurrence of atrial fibrillation (AF) and fibrosis marker soluble ST2 (sST2) in patients with nonvalvular paroxysmal AF (PAF).

Methods

We prospectively included 100 consecutive patients with PAF diagnosis and scheduled for cryoballoon catheter ablation for AF (47 males, 53 females; mean age 55.1±10.8 years). sST2 plasma levels were determined using the ASPECT-PLUS assay on ASPECT Reader device (Critical Diagnostics). The measurement range of these measurements was 12.5–250 ng/mL. Patients had regular follow-up visits with 12-lead electrocardiogram (ECG), medical history, and clinical evaluation. Twenty-four hours Holter ECG monitoring had been recorded 12 months after ablation.

Results

AF recurrence was detected in 22 patients after 1 year. Age, smoking history, diabetes mellitus,hypertension frequency, angiotensin converting enzyme inhibitor-angiotensin receptor blocker use, CHA₂DS₂VASc and HAS-BLED scores, serum sST2 level, left atrium (LA) end-diastolic diameter, LA volume and LA volume index were related to AF recurrence. In multivariable logistic regression analysis, sST2 was found to be only independent parameter for predicting AF recurrence (odds ratio, 1.085; p=0.001). Every 10-unit increase in sST2 was found to be associated with 2.103-fold increase in the risk of AF recurrence. The cut-off value of sST2 obtained by receiver operating characteristic curve analysis was 30.6 ng/mL for prediction of AF recurrence (sensitivity: 77.3%, specificity: 79.5%). The area under the curve was 0.831 (p<0.001).

Conclusions

sST2, which is associated with atrial fibrosis, can be thought to be a useful marker for detection of patients with high-grade fibrosis who will get less benefit from cryoablation.

S-R difference in V1-V2 is a novel criterion for differentiating the left from right ventricular outflow tract arrhythmias

AIM

The correct estimation of the VA origin as RVOT or LVOT results in reduced ablation duration reduced radiation exposure and decreased number of vascular access. In our study, we aimed to detect the predictive value of S-R difference in V1-V2 for differentiating the left from right ventricular outflow tract arrhythmias.

METHODS

We included 123 patients with symptomatic frequent premature ventricular outflow tract contractions who underwent successful catheter ablation (70 male, 53 female; mean age 46.2 ± 13.9 years, 61 RVOT, 62 LVOT origins). S-R difference in V1-V2 was calculated with this formula on the 12-lead surface ECG: (V1S + V2S) - (V1R + V2R). Conventional ablation was performed in 101 (82.1%) patients, CARTO electroanatomic mapping system was used in 22 (17.9%) patients.

RESULTS

V1-2 SRd was found to be significantly lower for LVOT origins than RVOT origins (p < .001). The cutoff value of V1-2 SRd obtained by ROC curve analysis was 1.625 mV for prediction of RVOT origin (sensitivity: 95.1%, specificity: 85.5%, positive predictive value: 86.5%, negative predictive value: 94.5%). The area under the curve (AUC) was 0.929 (p < .001).

CONCLUSION

S-R difference in V1-V2 is a novel and simple electrocardiographic criterion for accurately differentiating RVOT from LVOT sites of ventricular arrhythmia origins. The use of this simple ECG measurement could improve the accuracy of OTVA localization, could be beneficial for decreasing ablation duration and radiation exposure. Further studies with larger patient population are needed to verify the results of this study.

Coronary sinus lead delay index for optimization of coronary sinus lead placement

AIM

Optimization of coronary sinus (CS) lead position to the latest activated left ventricular (LV) area is important to increase cardiac resynchronization therapy (CRT) response. We aimed to detect the relationship between coronary sinus lead delay index (CSDI) and echocardiographic, electrocardiographic response to CRT treatment.

METHODS

We prospectively included 137 consecutive patients with heart failure (HF) diagnosis, QRS ≥ 120 ms, left bundle branch block (LBBB), New York Heart Association score (NYHA) II-IV, LV ejection fraction (LVEF) <35% and scheduled for CRT (84 male, 53 female; mean age 65.1 ± 10.1 years). Echocardiographic CRT response was defined as ≥15% reduction in LV end-systolic volume (LVESV). CS lead sensing delay was calculated as the time interval from the onset of surface QRS wave to the onset of depolarization wave recorded from the CS lead by using the CS pacing lead as a bipolar electrode. CSDI was calculated by dividing the CS lead sensing delay by the QRS duration.

RESULTS

LVESV reduction was associated with baseline QRS width (r = .257, p = .002), QRS narrowing (r = .396, p < .001), CSDI (r = .357, p < .001), and NT-proBNP (r = -0.213, p = .022) in bivariate analysis. In logistic regression analysis, CSDI was found to be only independent parameter for predicting significant LVESV reduction (Beta = 0.318, p < .001). CSDI was also found to be significantly associated with LVEF increase (r = .244, p = .004) and QRS narrowing (r = .178, p = .046).

CONCLUSION

CSDI may be used as a marker to predict the favorable response to CRT. It may be useful to integrate CSDI to CRT implantation procedure in order to minimize nonresponders.

A new use for maximum deflection index: Detection of intraventricular dyssynchrony

AIM

CRT has been shown to be very beneficial for patients with reduced LVEF, symptomatic HF and increased QRS width. But many patients do not benefit from CRT. Maximum deflection index (MDI) is a quantitive measure of the rapidity of depolarization of the myocardium. In previous studies, high MDI was found to indicate epicardial origin of ventricular tachycardia. We aimed to detect the relationship between echocardiographic intraventricular dyssynchrony and MDI.

METHODS

We included 144 patients with HF, QRS≥120ms, LBBB, NYHA II-IV, LVEF<35% and scheduled for CRT (90 male, 54 female; mean age 65.3±9.9years). Septal-lateral >60ms delay for the beginning of systolic velocity in TDI and septum-posterior >130ms delay in M-mode were accepted as intraventricular dyssynchrony. The MDI was calculated by dividing the time from onset of the QRS complex to the earliest point of maximum deflection in V5-V6 by the QRS duration.

RESULTS

Septal-lateral delay was associated with MDI and QRS width in bivariate analysis. In logistic regression analysis, MDI (beta=0,264, p=0.001) and QRS width (beta=0,177, p=0.028) were found to be independent parameters for predicting significant septal-lateral delay. MDI was also associated with significant septum-posterior delay in bivariate correlations and ROC curve (p<0.05 for all). In bivariate analysis MDI was associated with intraventricular dyssynchrony in both non-strict LBBB (r=0.261, p=0.010) and strict LBBB (r=0.305, p=0.035) groups.

CONCLUSION

MDI is closely associated with all echocardiographic intraventricular dyssynchrony parameters. We suggest that MDI may be used as a marker to detect patients with increased intraventricular dyssynchrony. It may be useful to integrate MDI to CRT patient selection procedure in order to minimize nonresponders.

High Left Ventricular Lead Sensing Delay Predicts QRS Narrowing and Good Response to Cardiac Resynchronization Therapy

BACKGROUND

Cardiac resynchronization therapy (CRT) was shown to improve heart failure (HF) prognosis. But many patients do not benefit from CRT. Optimization of left ventricular (LV) lead position to the latest activated LV area is important to increase CRT response. We aimed to detect the relationship between LV lead sensing delay and echocardiographic and electrocardiographic response to CRT treatment.

METHODS

We prospectively included 156 consecutive patients with HF diagnosis, QRS ≥ 120 ms, left bundle branch block, New York Heart Association II-IV, LV ejection fraction (LVEF) < 35%, and scheduled for CRT (100 male, 56 female; mean age 65.8 ± 10.06 years). Echocardiographic CRT response was defined as ≥15% reduction in LV end-systolic volume (LVESV). LV lead sensing delay was calculated as the time interval from the onset of surface QRS wave to the onset of depolarization wave recorded from the LV lead by using the LV pacing lead as a bipolar electrode.

RESULTS

LVESV reduction was associated with baseline QRS width (r = 0.292, P = 001), QRS narrowing (r = 0.332, P < 001), and LV lead sensing delay (r = 0.454, P < 001) in bivariate analysis. In logistic regression analysis, LV lead sensing delay was found to be the only independent parameter for predicting significant LVESV reduction (β = 0.423, P < 0.001). LV lead sensing delay was also found to be significantly associated with LVEF increase (r = 0.320, P < 0.001) and QRS narrowing (r = 0.345, P < 0.001).

CONCLUSION

LV lead sensing delay is the only independent predictor for significant reduction in LVESV and was found to be significantly associated with LVEF increase and QRS narrowing after CRT treatment. We suggest that LV lead sensing delay may be used as a marker to predict the favorable response to CRT.

Increased hs-CRP and decreased 1,25-dihydroxyvitamin D are associated with increased left ventricle lead threshold

PURPOSE

There are not enough data about threshold changes in patients with CRT. In this study, we aimed to investigate frequency of significant threshold increase of left ventricle lead and to determine clinical, demographic, medical and laboratory parameters that associated with threshold increase in CRT implanted patients.

METHODS

We included CRT implanted 200 patients (124 males, 76 females; mean age 65.8 ± 10.3 years) to this study. Basal and third month LV R wave amplitude, electrode impedance, and threshold values were recorded. Threshold increase was accepted as ≥0.1 V and significant increase as >1 V. Patients were divided into two groups: increased threshold and non-increased threshold for LV lead.

RESULTS

Number of patients with increased LV threshold was 68 (37.6 %). Furthermore, 8 % of patients had severe increase (≥1 V) in LV threshold. We observed that serum levels of hs-CRP and 1,25 (OH)2 vitamin D were independently associated with increased LV threshold. We showed that 1 mg/dl increase in hs-CRP and the 1 mg/dl decrease in vitamin D are associated with 25.3 and 4.5 % increase in the odds of increased LV threshold, respectively.

CONCLUSIONS

Increased hs-CRP and decreased 1,25 (OH)2 vitamin D are the strongest predictors of increased LV lead thresholds. We suggest that hs-CRP and 1,25 (OH)2 vitamin D may be used as markers to predict and follow the patients with increased thresholds. It may be useful to finalize CRT procedure with more appropriate basal threshold in patients with high serum hs-CRP and low 1,25 (OH)2 vitamin D levels.