Cardiac resynchronization therapy for pacing induced cardiomyopathy: Role of baseline right ventricular pacing burden.

BACKGROUND: Cardiac resynchronization therapy (CRT) is indicated for patients with heart failure with reduced left ventricular ejection fraction (LVEF) and chronic right ventricular (RV) pacing burden ≥40% (pacing-induced cardiomyopathy, PICM). It is uncertain whether baseline RV pacing burden impacts response to CRT. METHODS: We conducted a retrospective study of all CRT upgrades for PICM at our hospital from January 2017 to December 2018. Univariate and multivariable-adjusted changes in LVEF, and echocardiographic response (≥10% improvement in LVEF) at 3-12 months post-CRT upgrade were compared in those with RV pacing burden ≥90% versus <90%. RESULTS: We included 75 patients (age 74 ± 11 years, 71% male) who underwent CRT upgrade for PICM. The baseline RV pacing burden was ≥90% in 56 patients (median 99% [IQR 98%-99%]), and <90% in 19 patients (median 79% [IQR 73%-87%]). Improvement in LVEF was greater in those with baseline RV pacing burden ≥90% versus <90% (15.7 ± 9.3% vs. 7.5 ± 9.6%, p = .003). Baseline RV pacing burden ≥90% was a strong predictor of an improvement in LVEF ≥10% after CRT upgrade both in univariate and multivariate-adjusted models (p = .005 and .02, respectively). CONCLUSION: A higher baseline RV pacing burden predicts a greater improvement in LVEF after CRT upgrade for PICM.

UltraSound Axillary Vein Access (USAA): Learning curve and randomized comparison to traditional venous access for cardiac device implantation.

BACKGROUND: Many techniques exist for venous access (VA) during cardiac implantable electronic device (CIED) implantation. OBJECTIVE: We sought to evaluate the learning curve with ultrasound (US) guided axillary vein access (USAA). METHODS: Single-center prospective randomized controlled trial of patients undergoing CIED implantation. Patients were randomized in a 2:1 fashion to USAA versus conventional VA techniques. The primary outcomes were the success rates, VA times and 30-day complication rates. RESULTS: The study included 100 patients (age 68 ± 14 years, BMI 27 ± 4 kg/m2 ). USAA was successful in 66/70 implants (94%). Initial attempts at conventional VA included 47% axillary (n = 14), 30% (n = 9) cephalic, and 23% (n = 7) subclavian. The median access time was longer for USAA than conventional access (8.3 IQR 4.2-15.3 min vs. 5.2 IQR 3.4-8.6 min, p = .009). Among the five inexperienced USAA implanters, there was a significant improvement in median access time from first to last tertile of USAA implants (17.0 IQR 7.0-21.0 min to 8.6 IQR 4.5-10.8 min, p = .038). The experienced USAA implanter had similar access times with USAA compared with conventional access (4.0 IQR 3.3-4.7 min vs. 5.2 IQR 3.4-8.6 min, p = .15). Venograms were less common with USAA than conventional access (2% vs. 33%, p < .0001). The 30-day complication rate was similar with USAA (n = 4/70, 6%) versus conventional (n = 3/30, 10%, p = .44). CONCLUSION: Although the success rate with USAA was high, there was a significant learning curve. Once experienced with the USAA technique, there is the potential for reduced complications without adding to the procedure duration.

Ultrasound guided axillary vein access: An alternative approach to venous access for cardiac device implantation.

INTRODUCTION: Ultrasound guided axillary vein access (UGAVA) is an emerging approach for cardiac implantable electronic device (CIED) implantation not widely utilized. METHODS AND RESULTS: This is a retrospective, age and sex-matched cohort study of CIED implantation from January 2017 to July 2019 comparing UGAVA before incision to venous access obtained after incision without ultrasound (conventional). The study population included 561 patients (187 with attempted UGAVA, 68 ± 13 years old, 43% women, body mass index (BMI) 30 ± 8 kg/m2 , 15% right-sided, 43% implantable cardioverter-defibrillator, 15% upgrades). UGAVA was successful in 178/187 patients (95%). In nine patients where UGAVA was abandoned, the vein was too deep for access before incision. BMI was higher in abandoned patients than successful UGAVA (38 ± 6 vs. 28 ± 6 kg/m2 , p < .0001). Median time from local anesthetic to completion of UGAVA was 7 min (interquartile range [IQR]: 4-10) and median procedure time 61 min (IQR: 50-92). UGAVA changed implant laterality in two patients (avoiding an extra incision in both) and could have prevented unnecessary incision in four conventional patients. Excluding device upgrades, there was reduced fluoroscopy time in UGAVA versus conventional (4 vs. 6 min; IQR: 2-5 vs. 4-9; p < .001). Thirty-day complications were similar in UGAVA versus conventional (n = 7 vs. 26, 4 vs. 7%; p = .13, p = .41 adjusting for upgrades), partly driven by a trend towards reduced pneumothorax (n = 0 vs. 3, 0 vs. 1%; p = .22). CONCLUSIONS: UGAVA is a safe approach for CIED implantation and helps prevent an extra incision if a barrier is identified changing laterality preincision.