title: The Total Joint Arthroplasty Cardiac Risk Index for Predicting Perioperative Myocardial Infarction and Cardiac Arrest After Primary Total Knee and Hip Arthroplasty.
abstract: Current indices fail to consistently predict risk for major adverse cardiac events after major total joint arthroplasty.
  
  
  
  All primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) were identified from the National Surgical Quality Improvement Program data set. Based on prior analyses, age ≥80 years, history of hypertension, and history of cardiac disease were evaluated as predictors of myocardial infarction and cardiac arrest using stepwise multivariate logistic regression. A series of predictive scores were constructed and weighted to identify the influence of each variable on 30-day postoperative cardiac events, while comparing with the Revised Cardiac Risk Index (RCRI).
  
  
  
  Among 85,129 patients, age ≥80 years, hypertension, and a history of cardiac disease were all statistically significant predictors of postoperative cardiac events (0.32%; n = 275) after TKA and THA (P ≤ .02). Equal weighting of all variables maintained the highest discriminative capacity in both THA and TKA cohorts. Adjusted models explained 75% and 71% of the variation in postoperative cardiac events for those with THA and TKA, respectively, without statistically significant lack of fit (P = .52; P = .23, respectively). Conversely, the RCRI was not a significant predictor of postoperative cardiac events after TKA (odds ratio, 3.36; 95% CI, 0.19, 58.04; P = .40), although it maintained a similar discriminative capacity after THA (76%).
  
  
  
  The current total joint arthroplasty Cardiac Risk Index score was the most economical in predicting postoperative cardiac complication after primary unilateral TKA and THA. The RCRI was not a significant predictor of perioperative cardiac events for TKA patients but performed similarly to the current model for THA.
authors.affiliation: Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Waterman
authors.affiliation: Anderson Orthopaedic Clinic, Alexandria, Virginia.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Belmont
authors.affiliation: Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas; Department of Clinical Investigations, William Beaumont Army Medical Center, El Paso, Texas.
authors.forename: Julia O
authors.initials: JO
authors.lastname: Bader
authors.affiliation: Department of Orthopedic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Schoenfeld
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D006323:Heart Arrest / Q000209:etiology*; D006801:Humans; D007719:Knee Joint; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology*; D011183:Postoperative Complications / Q000209:etiology*; D020379:Risk Adjustment
keywords: cardiac complications; myocardial infarction; risk index; total hip arthroplasty; total knee arthroplasty