title: Management and outcome of patients with acute myocardial infarction presenting with pacemaker rhythm.
abstract: BACKGROUND
  Diagnosis of acute myocardial infarction (MI) is challenging in pacemaker patients. Little is known about this patient group.
  
  
  METHODS
  Patients with MI enrolled in the Swiss national AMIS Plus registry between January 2005 and December 2015 were analyzed. All patients with either paced ventricular rhythm or sinus rhythm with intrinsic ventricular conduction (IVC) were included in this study. Outcomes using crude data and propensity score matching were compared between patients with pacemaker rhythm and patients with IVC. The primary endpoint was in-hospital death.
  
  
  RESULTS
  Data from 300 patients with paced rhythm and 27,595 with IVC were analyzed. Patients with pacemaker rhythm were older (78.2y vs 65.4y; p<0.001), had more comorbidities (Charlson Index (CCI)>1: 54.0% vs 21.1%; p<0.001) and a higher rate of heart failure upon presentation (Killip class>2, 11.0% vs 5.9%; p<0.001) compared to patients with IVC. Door to balloon time in patients undergoing acute PCI is markedly delayed in contrast to patients with IVC (280min vs 85min; p<0.001). Consequently, crude mortality in patients with pacemakers was high (11.3% vs 4.6%; p<0.001). However, when analyzed with propensity matching for gender, age, CCI>1 and Killip>2, mortality was similar (11.2% vs 10.5%; p=0.70).
  
  
  CONCLUSIONS
  Pacemaker patients with acute MI represent a high-risk group with doubled crude mortality compared to patients without pacemakers, due to higher age and higher Killip class. Diagnosis is difficult and results in delayed treatment. Treatment algorithms for MI with paced rhythm should possibly be adapted to those used for STEMI or new left bundle branch block.
  
  
  BACKGROUND
  NCT01305785.
authors.affiliation: University of Zurich, AMIS Plus Data Center, Epidemiology, Biostatistics and Prevention Institute, 8001 Zurich, Switzerland.
authors.forename: Noemi
authors.initials: N
authors.lastname: Bertel
authors.affiliation: University of Zurich, AMIS Plus Data Center, Epidemiology, Biostatistics and Prevention Institute, 8001 Zurich, Switzerland.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Witassek
authors.affiliation: University of Zurich, Epidemiology, Biostatistics and Prevention Institute, 8001 Zurich, Switzerland.
authors.forename: Milo
authors.initials: M
authors.lastname: Puhan
authors.affiliation: University of Zurich, AMIS Plus Data Center, Epidemiology, Biostatistics and Prevention Institute, 8001 Zurich, Switzerland; University of Basel, Department of Biomedicine, 4031 Basel, Switzerland.
authors.forename: Paul
authors.initials: P
authors.lastname: Erne
authors.affiliation: Department of Cardiology, Kantonsspital St. Gallen, 9007 St. Gallen, Switzerland.
authors.forename: Hans
authors.initials: H
authors.lastname: Rickli
authors.affiliation: Department of Cardiology, HerzGefässZentrum Zürich, 8038 Zurich, Switzerland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Naegeli
authors.affiliation: Department of Cardiology, Cardiocentro Ticino, 6900 Lugano, Switzerland.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pedrazzini
authors.affiliation: Department of Cardiology, Hôpital cantonal HFR, 1708 Fribourg, Switzerland.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Stauffer
authors.affiliation: University of Zurich, AMIS Plus Data Center, Epidemiology, Biostatistics and Prevention Institute, 8001 Zurich, Switzerland. Electronic address: dragana.radovanovic@uzh.ch.
authors.forename: Dragana
authors.initials: D
authors.lastname: Radovanovic
mesh_terms: D000368:Aged; D000465:Algorithms; D002037:Bundle-Branch Block / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006352:Heart Ventricles / Q000503:physiopathology*; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000150:complications / Q000401:mortality / Q000601:surgery*; D009204:Myocardial Revascularization / Q000379:methods*; D010138:Pacemaker, Artificial; D057216:Propensity Score; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013557:Switzerland / Q000453:epidemiology; D015912:Thrombolytic Therapy / Q000379:methods*
keywords: AMIS Plus; Heart rhythm; Myocardial infarction; Pacemaker; Sinus rhythm