title: Clinical features and prognosis of type 2 myocardial infarction in vasospastic angina.
abstract: BACKGROUND
  Although generally the prognosis of vasospastic angina is considered excellent, vasospasm has been shown to be a cause of type 2 myocardial infarction. This study was performed to investigate the clinical characteristics and prognosis of patients with vasospastic angina complicated with type 2 myocardial infarction.
  
  
  METHODS
  We performed a retrospective analysis of 171 consecutive patients with definite vasospastic angina (median age, 64 years; 55.0% were male) who visited the Kameda Medical Center with chest pain and in whom cardiac troponin I level was measured between 2005 and 2013. The patients were divided into type 2 myocardial infarction and non-type 2 myocardial infarction groups. A diagnosis of type 2 myocardial infarction was based on a serum cardiac troponin I value >99th percentile upper reference limit. The primary end point was a combination of nonfatal myocardial infarction or death by any cause.
  
  
  RESULTS
  A total of 42 patients (24.6%) were diagnosed with type 2 myocardial infarction, and the type 2 myocardial infarction group had a higher incidence of combined end point than the non-type 2 myocardial infarction group during the median follow-up of 4.4 years (26.2% vs 9.3%, respectively, P = .008). Type 2 myocardial infarction remained an independent predictor of combined end point even after adjusting by the Japanese Coronary Spasm Association risk factors for combined end point (hazard ratio, 2.84; 95% confidence interval, 1.22-6.61; P = .02).
  
  
  CONCLUSIONS
  Approximately one quarter of patients with vasospastic angina were associated with type 2 myocardial infarction, and this population should be identified as a new high-risk subgroup of those with vasospastic angina requiring an alternative treatment strategy.
authors.affiliation: Department of Cardiology, Kameda Medical Center, Chiba, Japan; Department of Life Science and Bioethics, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: yuya8950@gmail.com.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Matsue
authors.affiliation: Department of Rheumatology, Kameda Medical Center, Chiba, Japan; Department of Epidemiology, Harvard School of Public Health, Boston, Mass.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Cardiology, Kameda Medical Center, Chiba, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hoshino
authors.affiliation: Department of Cardiology, Kameda Medical Center, Chiba, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Yonetsu
authors.affiliation: Department of Cardiology, Kameda Medical Center, Chiba, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Cardiology, Kameda Medical Center, Chiba, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Matsumura
authors.affiliation: Department of Cardiology, Kameda Medical Center, Chiba, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hashimoto
authors.affiliation: Department of Life Science and Bioethics, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yoshida
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000453:epidemiology / Q000209:etiology*; D003329:Coronary Vasospasm / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology* / Q000628:therapy; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Prognosis; Troponin; Type 2 myocardial infarction; Vasospasm