title: Heart rate variables in the Vascular Quality Initiative are not reliable predictors of adverse cardiac outcomes or mortality after major elective vascular surgery.
abstract: OBJECTIVE
  Heart rate (HR) parameters are known indicators of cardiovascular complications after cardiac surgery, but there is little evidence of their role in predicting outcome after major vascular surgery. The purpose of this study was to determine whether arrival HR (AHR) and highest intraoperative HR are associated with mortality or major adverse cardiac events (MACEs) after elective vascular surgery in the Vascular Quality Initiative (VQI).
  
  
  METHODS
  Patients undergoing elective lower extremity bypass (LEB), aortofemoral bypass (AFB), and open abdominal aortic aneurysm (AAA) repair in the VQI were analyzed. MACE was defined as any postoperative myocardial infarction, dysrhythmia, or congestive heart failure. Controlled HR was defined as AHR <75 beats/min on operating room arrival. Delta HR (DHR) was defined as highest intraoperative HR - AHR. Procedure-specific MACE models were derived for risk stratification, and generalized estimating equations were used to account for clustering of center effects. HR, beta-blocker exposure, cardiac risk, and their interactions were explored to determine association with MACE or 30-day mortality. A Bonferroni correction with P < .004 was used to declare significance.
  
  
  RESULTS
  There were 13,291 patients reviewed (LEB, n = 8155 [62%]; AFB, n = 2629 [18%]; open AAA, n = 2629 [20%]). Rates of any preoperative beta-blocker exposure were as follows: LEB, 66.5% (n = 5412); AFB, 57% (n = 1342); and open AAA, 74.2% (n = 1949). AHR and DHR outcome association was variable across patients and procedures. AHR <75 beats/min was associated with increased postoperative myocardial infarction risk for LEB patients across all risk strata (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.03-1.9; P = .03), whereas AHR <75 beats/min was associated with decreased dysrhythmia risk (OR, 0.42; 95% CI, 0.28-0.63; P = .0001) and 30-day death (OR, 0.50; 95% CI, 0.33-0.77; P = .001) in patients at moderate and high cardiac risk. These HR associations disappeared in controlling for beta-blocker status. For AFB and open AAA repair patients, there was no significant association between AHR and MACE or 30-day mortality, irrespective or cardiac risk or beta-blocker status. DHR and extremes of highest intraoperative HR (>90 or 100 beats/min) were analyzed among all three operations, and no consistent associations with MACE or 30-day mortality were detected.
  
  
  CONCLUSIONS
  The VQI AHR and highest intraoperative HR variables are highly confounded by patient presentation, operative variables, and beta-blocker therapy. The discordance between cardiac risk and HR as well as the lack of consistent correlation to outcome makes them unreliable predictors. The VQI has elected to discontinue collecting AHR and highest intraoperative HR data, given insufficient evidence to suggest their importance as an outcome measure.
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Fla. Electronic address: salvatore.scali@surgery.ufl.edu.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Scali
authors.affiliation: Division of Vascular Surgery, University of Vermont, Burlington, Vt.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bertges
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Fla.
authors.forename: Daniel
authors.initials: D
authors.lastname: Neal
authors.affiliation: Division of Vascular Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Virendra
authors.initials: V
authors.lastname: Patel
authors.affiliation: Division of Vascular Surgery, Maine Medical Center, Portland, Me.
authors.forename: Jens
authors.initials: J
authors.lastname: Eldrup-Jorgensen
authors.affiliation: Section of Vascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH.
authors.forename: Jack
authors.initials: J
authors.lastname: Cronenwett
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Fla.
authors.forename: Adam
authors.initials: A
authors.lastname: Beck
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D017558:Elective Surgical Procedures; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D058729:Peripheral Arterial Disease / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D011237:Predictive Value of Tests; D019984:Quality Indicators, Health Care / Q000592:standards; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014656:Vascular Surgical Procedures / Q000009:adverse effects* / Q000401:mortality / Q000592:standards
chemical_list: D000319:Adrenergic beta-Antagonists