Preoperative Noninvasive Cardiac Testing in Older Adults With Hip Fracture

A Multi-Site Study

Liron Sinvani, MD; Daniel A. Mendelson, MD; Ankita Sharma, DO; Christian N. Nouryan, MA; Joanna S. Fishbein, MPH; Michael G. Qiu, PhD, MD; Roman Zeltser, MD; Amgad N. Makaryus, MD; Gisele P. Wolf-Klein, MD

Disclosures

J Am Geriatr Soc. 2020;68(8):1690-1697. 

In This Article

Discussion

Hip fractures commonly occur in older adults and lead to increased morbidity, mortality, and healthcare expenditures.[4–7] Timely surgical repair in this population improves clinical outcomes and quality of life.[25] Yet surgical repair is often delayed for the purpose of preoperative noninvasive cardiac testing.[26] In this study, we evaluated older adults hospitalized with hip fracture, the factors associated with the use of preoperative pharmacologic stress testing and TTE, as well as their associations with TTS, LOS, and in-hospital mortality. Our study highlights the low preoperative utilization rate of pharmacologic stress testing (<1%) and the high rate of TTE (1 in 3). Recent studies demonstrated similar trends (18%-27%) in preoperative noninvasive cardiac testing.[12,26] Because NST is more time consuming, physicians may perceive TTE as a more time-efficient snapshot process for cardiac status evaluation.

Our study supports previous literature demonstrating a higher rate of TTE use on the medical service, as opposed to the surgical service, and in community hospitals, as opposed to tertiary centers.[27] It is likely that the increased use of TTE for patients admitted to the medical service relates to natural selection, namely more complex patients with a greater number of comorbidities and complication risks (American Society of Anesthesiologist class ≥4). In addition, the higher use of TTE in community hospitals could be related to customary practices in these settings.

Previous studies clearly highlighted improved outcomes when proceeding with surgical repair within 48 hours of hip fracture.[25] A case-control study by Mutlu et al. demonstrated that when surgical repair was delayed for more than 48 hours for preoperative cardiac testing, mortality increased by 19.7%.[11] Furthermore, recent data suggest that the optimal TTS should be less than 24 hours.[19,24] In this study, the median TTS among those with preoperative TTE (n = 370) was 37.3 hours compared with 24.4 hours in the group without a preoperative TTE (n = 709). Therefore, because TTE could be a factor in prolonging the preoperative period above the recommended safe time limit, the risk of delaying surgery must be weighed with the benefit of the TTE findings.

With regard to LOS, the univariate model demonstrated a trend toward increased LOS with those patients undergoing TTE. Although the trend was not significant, an increased LOS of .7 days in the TTE group is clinically relevant for improved patient outcomes.[28] Our study demonstrates that although preoperative TTE, on its own, is not associated with LOS, it appears that TTS is associated with increased LOS. In other words, presurgical TTE does not appear to be associated with LOS after surgery (defined as LOS from time of surgery until discharge), but a TTE that prolongs TTS may indirectly affect LOS. This finding is consistent with previous studies that demonstrated a similar relationship of TTE and LOS.[29]

Previous studies that evaluated the appropriateness of preoperative TTE noted that the rate of adherence to the guidelines was 66% over the 3.5-year study period.[30–32] In the study by Adair et al., no significant heart disease was found in any of the 34 patients who underwent a TTE that had not been indicated by the guideline criteria, and 14 of the 66 patients (21%) for whom an echocardiogram was indicated by the criteria were found to have heart conditions serious enough to modify anesthesia or medical management.[30] Other studies indicated that TTEs are frequently obtained outside standard recommendations.[32,33] Because most preoperative orders (55%) and specifically preoperative TTEs (54%) were nonspecific, the evaluation of TTE indication and its potential correlation to a change in the therapeutic management is beyond the scope of this study.

It is uncertain whether TTE ultimately leads to changes in pre-, peri-, or postoperative management.[12,34–37] On the one hand, the use of TTE is associated with prolonged TTS, which was associated with poor outcomes without a real change in managment.[11,25,38] On the other hand, characterization of cardiac function and evaluation of undiagnosed heart murmurs by TTE was proposed before anesthesia to better evaluate cardiac risk.[11,37,38] Others propose that perioperative point-of-care ultrasound may offer benefits in the diagnosis of important perioperative conditions.[11,39,40] The 2014 ACC/AHA guidelines state that "Further studies are required to determine if the information obtained from the assessment of ventricular function in patients without signs or symptoms adds incremental information that will result in changes in management and outcome such that the appropriateness criteria should be updated."[10]

This study is not without limitations. Although our study demonstrated a high proportion of preoperative TTE in older patients with hip fracture, one major limitation was the lack of electronic medical record documentation needed to account for acute cardiac disease and other relevant comorbidities that might indicate the appropriateness of TTE. It is possible that a preoperative TTE is a marker for a sicker patient population. However, as indicated by the documented preoperative TTE indications and previous literature, the high rate of preoperative TTE almost certainly represents an overutilization.[30–33]

Further studies are needed to determine the effect of preoperative TTE on TTS by including patient-level variables such as relevant acute conditions (acute coronary syndrome, acute heart failure) and illness severity (vital signs and selected laboratory tests). In addition, although data from seven diverse hospitals were included, it is of note that they were all from a single health system. Therefore, generalizability to other health systems is unknown. Despite the relatively homogeneously defined cohort and adjustment for various factors that could influence TTS, LOS, and inhospital mortality, unmeasured differences may still account for variations. Lastly, although we addressed in-hospital mortality, the study was not geared to provide data on postdischarge mortality.

The study highlights the high preoperative utilization rate of TTE in older patients admitted with hip fracture. Given that the risk-benefit ratio is lowest when the surgery is performed within 24 to 48 hours after injury (midlevel recommendation) and TTE has the potential to delay surgical repair, preoperative examination should not compromise the optimal intervention time unless it will change/inform management.[41] Thus integration of clinical practice guidelines such as the ACC/AHA guidelines into a perioperative protocol has the potential to improve the efficiency of preoperative evaluation, reduce resource utilization, and reduce the TTS without sacrificing patient safety. In addition, comanagement models of geriatrics or hospitalist and orthopedics services may help reduce the variability of TTE utilization among services and hospitals.[42–48] Further studies should explore the driving force and decision-making process of TTE ordering.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....