title: Cardiac resynchronization therapy in patients with postero-lateral scar by cardiac magnetic resonance: A systematic review and meta-analysis.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in selected patients with heart failure, but up to one third of patients may not respond to CRT. A transmural postero-lateral (TMPL) wall scar in the left ventricle (LV) or over the LV pacing site may attenuate clinical and echocardiographic response to CRT.
  
  
  RESULTS
  We systematically searched PubMed, EMBASE, and Cochrane databases for studies examining the association between Cardiac magnetic resonance (CMR)-determined postero-lateral or LV pacing site scar and clinical and echocardiographic response to CRT. Eleven prospective studies were included. The presence of TMPL scar on pre-implant CMR was associated with a 75% lower chance of echocardiographic response to CRT, and a similarly lower chance of clinical response. Significant scar over LV pacing site on pre-implant CMR was also associated with a 46% lower chance of echocardiographic response to CRT, and a 67% lower chance of clinical response.
  
  
  CONCLUSIONS
  The presence of transmural postero-lateral scar or significant scar within the LV pacing site detected by pre-implant CMR is associated with a lower rate of clinical or echocardiographic response to CRT.
authors.affiliation: Section of Adult Cardiology, Cardiovascular Department, King Faisal Specialist Hospital & Research Center, Jeddah, Kingdom of Saudi Arabia. Electronic address: amindaoulah@yahoo.com.
authors.forename: Amin
authors.initials: A
authors.lastname: Daoulah
authors.affiliation: Institute of Cardiac Sciences, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates; Tufts Clinical and Translational Science Institute, Department of Medicine, Tuft University School of Medicine, Boston, MA, USA.
authors.forename: Alawi A
authors.initials: AA
authors.lastname: Alsheikh-Ali
authors.affiliation: Section of Pulmonology, Internal Medicine Department, King Faisal Specialist Hospital & Research Center, Jeddah, Kingdom of Saudi Arabia.
authors.forename: Salem M
authors.initials: SM
authors.lastname: Al-Faifi
authors.affiliation: University of Alabama School of Medicine, Huntsville Regional Medical Campus, Huntsville, AL, USA.
authors.forename: Sara R
authors.initials: SR
authors.lastname: Ocheltree
authors.affiliation: Section of Adult Cardiology, Cardiovascular Department, King Faisal Specialist Hospital & Research Center, Jeddah, Kingdom of Saudi Arabia.
authors.forename: Ejazul
authors.initials: E
authors.lastname: Haq
authors.affiliation: University of Toronto, Toronto, Ontario, Canada; McMaster University, Hamilton, Ontario, Canada.
authors.forename: Farhan M
authors.initials: FM
authors.lastname: Asrar
authors.affiliation: Section of Adult Cardiology, Cardiovascular Department, King Faisal Specialist Hospital & Research Center, Jeddah, Kingdom of Saudi Arabia.
authors.forename: Adnan
authors.initials: A
authors.lastname: Fathey
authors.affiliation: Division of Cardiothoracic Surgery and Cardiac Surgery Intensive Care Unit, King Faisal Specialist Hospital and Research Center, Jeddah, Kingdom of Saudi Arabia.
authors.forename: Ali Ahmed
authors.initials: AA
authors.lastname: Haneef
authors.affiliation: Section of Pediatric Cardiology, Cardiovascular Department, King Faisal Specialist Hospital & Research Center, Jeddah, Kingdom of Saudi Arabia.
authors.forename: Faris
authors.initials: F
authors.lastname: Al Mousily
authors.affiliation: Section of Adult Cardiology, Cardiovascular Department, King Faisal Specialist Hospital & Research Center, Jeddah, Kingdom of Saudi Arabia.
authors.forename: El-Sayed
authors.initials: el-S
authors.lastname: O
authors.affiliation: Division of Cardiology, Baystate Medical Center, Tufts University School of Medicine, Springfield, MA, USA.
authors.forename: Amir
authors.initials: A
authors.lastname: Lotfi
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000706:statistics & numerical data*; D002921:Cicatrix / Q000453:epidemiology* / Q000473:pathology* / Q000628:therapy; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy*; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
keywords: Cardiac magnetic resonance; Cardiac resynchronization therapy; Scar