Introduction: Right ventricular (RV) pacing, which is the standard treatment for patients with bradycardia, results in a broad QRS complex with dyssynchronous left ventricular contraction. Long-term RV pacing is associated with adverse remodelling of the left ventricular, which can contribute to, or cause, left ventricular (LV) systolic dysfunction, and heart failure (HF). A specialist clinic for patients with pacemakers approaching elective replacement indicator (ERI) and high RV pacing burden has been established. The patients were referred if RV pacing percentage > 40% and 12–18 months left on the battery. The clinic was run by a consultant, along with highly specialised cardiac physiologists. As well as the usual pacing checks, a full clinical assessment was carried out, along with a medication review and 12 lead ECG. Referral to echocardiography was made if no recent echo was available.
Methods: This retrospective audit followed 75 patients with pacemakers who were referred to the upgrade clinic between January 2022 and December 2022. The patient health records were reviewed to collect specific information on the patient, such as patient ID, age, sex, pacing system (VR/DR), RV lead location (RVA or RVS), RV pacing percentage, QRS width with pacing, underlying rhythm, aetiology, AF burden percentage, NYHA class, LV ejection fraction, upgrade to CRT device within one year of EUR.
Results: Of the 75 patients, 17 were recommended for CRT upgrade at the time of EUR. Of the 17 patients in the CRT upgrade group, 88% were male; mean age was 82 ± 8 years, mean QRS width 176 ± 17 msec, mean LV ejection fraction (LVEF) was 38 ± 9%, classed as NYHA II were 35% and NYHA III were 53%. 76% of the patients in CRT upgrade group had persistent AF, P=0.04. Of the 58 patients in the standard EUR group, 65% were male; mean age was 79 ± 11 years, mean QRS width 163 ± 19 msec, mean LV ejection fraction (LVEF) was 52 ± 7 %; classed as NYHA I were 47%, NYHA II were 43% and NYHA III were 10%. Patients were not just assessed for CRT upgrade, 18% had medications optimized and 14% had device settings changed to minimize RV pacing when possible. There is no significant difference in patients with single or dual chamber systems between the two groups (P=0.77); combining this with the AF data suggests that a lot of the initial implants were for patients in sinus rhythm who have subsequently deteriorated to AF and no difference in RV lead position between groups (P= 0.18). There was a significant difference in paced QRS width (P=0.03), LV ejection fraction (P<0.01) and in NYHA class between the groups (P<0.01). Of the 17 patients recommended for CRT-P upgrade, 2 patients had a failed LV lead placement (difficult CS anatomy and left sided SVC with dilated CS) and 2 patients were converted to standard EUR on the day of the procedure. There were 2 procedure related complications, both in the CRT-P upgrade group. One patient had a small haematoma (no drain required), and the other one had significant issues with phrenic nerve stimulation that eventually led to the LV lead being programmed off.
Conclusions: This retrospective audit has demonstrated that the time of EUR is a great opportunity to assess and optimize patient medical and device therapy, identifying patients with important LV systolic dysfunction but few symptoms. Implementing it has led to a significant increase in the number of CRT-P upgrades at EUR, with no upgrades within the following 12 months of standard EUR whilst there were 2 patients in the previous year who required CRT upgrade within 12 months of EUR. ❑
