Risk factors for cardiac complications after spine surgery

ABSTRACT

 

Study design: Registry study using prospectively collected data

Objective: To determine risk factors for cardiac complications in spine surgery.

Methods: The Spine End Results Registry 2003–2004 is an exhaustive database of 1,592 patients who underwent spine surgery at the University of Washington Medical Center or Harborview Medical Center. Detailed information regarding patient demographic, medical comorbidity, surgical invasiveness and adverse outcomes were prospectively recorded. The primary outcome of measure was the occurrence of a cardiac complication in the perioperative period. Relative risk (RR) and 95 % confidence intervals were calculated for each of the categorical variables. Multiple log-binomial regression analysis was performed to investigate the independent factors associated with cardiac complication.

Results: The incidence of cardiac complication after spine surgery was 6.7 %. There were 136 cardiac complications in 107 patients after spine surgery. Age, diabetes, previous cardiac history, elevated adjusted Charlson comorbidity score, revision surgery, combined anterior-posterior approaches, and surgical invasiveness were statistically significant risk factors for cardiac complication after spine surgery.

Conclusions: The results of the present study suggest numerous statistically significant risk factors for cardiac complications after spine surgery. These results may aid the clinician with preoperative risk stratification and patient counseling.

STUDY RATIONALE Numerous studies have examined the morbidity and mortality of spine surgery 1 2 3 4 5 6 7 8 9, however, there is a paucity of literature examining the occurrence of cardiac complications after spine surgery. Cardiac complications are a leading cause of death after non-cardiac surgery 4 5 10. Lee et al reported a 0.8 % incidence of cardiac complications after lumbar fusion in retrospective review of 901 patients 11, but identification of statistically significant risk factors was limited by the study methodology. OBJECTIVE The objective of this study is to identify risk factors for cardiac complications after spine surgery.

References

• 1 Carreon L Y, Puno R M, Dimar 2nd J R. et al . Perioperative complications of posterior lumbar decompression and arthrodesis in older adults.  J Bone Joint Surg Am. 2003;  85-A(11) 2089-2092
• 2 Cassinelli E H, Eubanks J, Vogt M. et al . Risk factors for the development of perioperative complications in elderly patients undergoing lumbar decompression and arthrodesis for spinal stenosis: an analysis of 166 patients.  Spine. 2007;  32(2) 230-235
• 3 Deyo R A, Cherkin D C, Loeser J D. et al . Morbidity and mortality in association with operations on the lumbar spine. The influence of age, diagnosis, and procedure.  J Bone Joint Surg Am. 1992;  74(4) 536-543
• 4 Faciszewski T, Jensen R, Rokey R. et al . Cardiac risk stratification of patients with symptomatic spinal stenosis.  Clin Orthop Relat Res. 2001;  (384) 110-115
• 5 Hertzer N R, Beven E G, Young J R. et al . Coronary artery disease in peripheral vascular patients. A classification of 1000 coronary angiograms and results of surgical management.  Ann Surg. 1984;  199(2) 223-233
• 6 Kalanithi P S, Patil C G, Boakye M. National complication rates and disposition after posterior lumbar fusion for acquired spondylolisthesis.  Spine (Phila Pa 1976). 2009;  34(18) 1963-1969
• 7 Patel N, Bagan B, Vadera S. et al . Obesity and spine surgery: relation to perioperative complications.  J Neurosurg Spine. 2007;  6(4) 291-297
• 8 Raffo C S, Lauerman W C. Predicting morbidity and mortality of lumbar spine arthrodesis in patients in their ninth decade.  Spine. 2006;  31(1) 99-103
• 9 Vaidya R, Carp J, Bartol S. et al . Lumbar spine fusion in obese and morbidly obese patients.  Spine. 2009;  34(5) 495-500
• 10 Mangano D T. Perioperative cardiac morbidity.  Anesthesiology. 1990;  72(1) 153-184
• 11 Lee D Y, Lee S H, Jang J S. Risk factors for perioperative cardiac complications after lumbar fusion surgery.  Neurol Med Chir (Tokyo). 2007;  47(11) 495-500
• 12 Mirza S K, Deyo R A, Heagerty P J. et al . Towards standardized measurement of adverse events in spine surgery: conceptual model and pilot evaluation.  BMC Musculoskelet Disord. 2006;  7 53
• 13 Mirza S K, Deyo R A, Heagerty P J. et al . Development of an index to characterize the „invasiveness” of spine surgery: validation by comparison to blood loss and operative time.  Spine. 2008;  33(24) 2651-2661; discussion 2662
• 14 Charlson M E, Pompei P, Ales K L. et al . A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.  J Chronic Dis. 1987;  40(5) 373-383
• 15 Li G, Patil C G, Lad S P. et al . Effects of age and comorbidities on complication rates and adverse outcomes after lumbar laminectomy in elderly patients.  Spine. 2008;  33(11) 1250-1255

EDITORIAL STAFF PERSPECTIVES

This study touches upon a type of complication frequently overlooked in spine surgery. Cardiac and other internal medical complications are commonly assumed to be covered by other specialties, such as Anesthesia or Medical specialties and are therefore overlooked by surgical specialties such as ours. However, as this study shows, subspecialties such as Spine have very specific concerns, which are not specifically addressed by anyone but us.

Possible short comings of this study concern lack of control of variables typical for a retrospective study such as this. For cardiac conditions this may include perioperative beta-blockade or absence thereof, use of chemical thrombembolism prophylaxis and utilization of Intensive Care facilities for at-risk patients. The value of this study however lies in this cohort size and diversity of conditions treated. It may direct us to utilize preoperative medicine consult services to optimize preoperative preparations for at-risk patients and may help us counsel patients more honestly.