Association Between Global Longitudinal Strain and Pacing-Induced Cardiomyopathy: A Systematic Review and Meta-Analysis.

BACKGROUND: High right ventricular pacing burden is a well-established risk factor for the development of left ventricular dysfunction and pacing-induced cardiomyopathy (PICM). However, identification of post-implant patients at risk for PICM remains challenging. This meta-analysis evaluated the association between global longitudinal strain (GLS) by speckle tracking echocardiography (STE) and the risk of subsequent development of PICM in patients who undergo pacemaker implantation. METHODS: We searched the databases PubMed, Embase, and Web of Science for studies reporting an association between early (<1 month) and late (>1 month) post-implant GLS measurement and subsequent development of PICM on long-term follow-up. The search was not restricted to time or publication status. Results were reported as mean difference (MD) with 95% confidence intervals (CIs) and p values. RESULTS: A total of 6 studies with 455 patients (74 with eventual PICM, 381 without PICM) met inclusion criteria. The mean follow-up was 15 months, mean age was 69.2 years, and 48.6% were men. The mean ventricular pacing burden was 88.8%. Both early post-implant GLS (MD 4.98, 95% CI 3.84-6.12; p < 0.01) and long-term post-implant GLS (MD 5.35, 95% CI 3.83-6.88; p < 0.01) were significantly reduced in patients who eventually developed PICM; a positive MD indicates a less negative (more impaired) GLS in the PICM group. CONCLUSIONS: GLS values are significantly reduced both early and late after pacemaker implantation in patients who subsequently develop PICM. Impaired post-implant GLS measured by STE was associated with an increased risk of subsequently developing PICM. Whether GLS can be used to identify at-risk patients in clinical practice remains to be established in prospective studies.