title: Improve the prevention of sudden cardiac arrest in emerging countries: the Improve SCA clinical study design.
abstract: OBJECTIVE
  This study aims to demonstrate that primary prevention (PP) patients with one or more additional risk factors are at a similar risk of life-threatening ventricular arrhythmias when compared with secondary prevention (SP) patients, and would receive similar benefit from an implantable cardioverter defibrillator (ICD), or cardiac resynchronization therapy-defibrillator (CRT-D) implant. The study evaluates the benefits of therapy for high-risk patients in countries where defibrillation therapy for PP of SCA is underutilized.
  
  
  METHODS
  Enrolment will consist of 4800 ICD-eligible patients from Asia, Latin America, Eastern Europe, the Middle East, and Africa. Upon enrolment, patients will be categorized as SP or PP. Primary prevention patients will be assessed for additional risk factors: syncope/pre-syncope, non-sustained ventricular tachycardia, frequent premature ventricular contractions, and low left ventricular ejection fraction. Those PP patients with one or more risk factors will be categorized as '1.5' patients. Implant of an ICD/CRT-D will be left to the patient and/or physician's discretion. The primary endpoint will compare the appropriate ICD therapy rate between SP and 1.5 patients. The secondary endpoint compares mortality between 1.5 implanted and non-implanted patients.
  
  
  CONCLUSIONS
  The Improve SCA study will investigate a subset of PP patients, believed to be at similar risk of life-threatening ventricular arrhythmias as SP patients. Results may help clinicians identify and refer the highest risk PP patients for ICDs, help local societies expand guidelines to include PP of SCA utilizing ICDs, and provide additional geographical-relevant evidence to allow patients to make an informed decision whether to receive an ICD.
  
  
  BACKGROUND
  NCT02099721.
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, 167 North Lishi Road, Beijing 100037, China zsfuwai@vip.163.com.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Medanta, The Medicity Hospital, Sector 38, Gurgaon, Haryana 122041, India.
authors.forename: Balbir
authors.initials: B
authors.lastname: Singh
authors.affiliation: Instituto de Cardiologia - Fundacion Cardioinfantil, Centro Internacional de Arritmias Calle 163 A #13B- 60, Bogota, Colombia.
authors.forename: Diego A
authors.initials: DA
authors.lastname: Rodriguez
authors.affiliation: Republican Scientific Practical Centre Cardiology, R. Luxembourg Str. 110, Minsk 220036, Belarus.
authors.forename: Alexandr Robertovich
authors.initials: AR
authors.lastname: Chasnoits
authors.affiliation: Institut Jantung Negara, 145 Jalan Tun Razak, Kuala Lumpur 50400, Malaysia.
authors.forename: Azlan
authors.initials: A
authors.lastname: Hussin
authors.affiliation: National Heart Centre Singapore, 5 Hospital Avenue, Singapore 169609, Singapore.
authors.forename: Chi-Keong
authors.initials: CK
authors.lastname: Ching
authors.affiliation: West China Hospital, Sichuan University, No. 37 Guo Xue St., Chengdu 610041, China.
authors.forename: Dejia
authors.initials: D
authors.lastname: Huang
authors.affiliation: Cardiovascular Center, 5/F, National Taiwan University Hospital, No. 7, Chung Shan S. Rd, Zhong Zheng District, Taipei City 10002, Taiwan.
authors.forename: Yen-Bin
authors.initials: YB
authors.lastname: Liu
authors.affiliation: Medtronic, CRHF Clinical Research, 8200 Coral Sea Street NE, Mounds View, Minneapolis, MN 55112, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Cerkvenik
authors.affiliation: Medtronic, CRHF Clinical Research, 8200 Coral Sea Street NE, Mounds View, Minneapolis, MN 55112, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Willey
authors.affiliation: Korea University Medical Center, A126-1 5th St. Anam-dong Sungbuk-ku, Seoul 136-705, Korea.
authors.forename: Young-Hoon
authors.initials: YH
authors.lastname: Kim
mesh_terms: D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects; D058409:Cardiac Resynchronization Therapy Devices; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D019049:Developed Countries; D004554:Electric Countershock / Q000009:adverse effects / Q000295:instrumentation; D006801:Humans; D018579:Patient Selection; D011322:Primary Prevention / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D012107:Research Design; D018570:Risk Assessment; D012307:Risk Factors; D055502:Secondary Prevention / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome
keywords: LVEF; NSVT; PVCs; Primary prevention; SCA; Secondary prevention; Syncope