# Examining safety of cardiac surgery in patients with preoperative cardiac arrest

## TL;DR

This study finds that delaying cardiac surgery in patients who had a cardiac arrest before surgery may reduce in-hospital deaths but increase other complications.

## Contribution

The study provides new evidence on the safety and outcomes of delaying cardiac surgery after preoperative cardiac arrest.

## Key findings

- Delayed surgery was linked to lower in-hospital mortality but higher odds of thromboembolic and infectious complications.
- Delaying surgery was associated with reduced daily hospital costs without increasing neurological complications.
- The study suggests delaying surgery is safe for patients who can tolerate at least 24 hours of delay.

## Abstract

Although postoperative cardiac arrest is a well-studied complication of cardiac surgery, few guidelines exist regarding timing of surgery in preoperative cardiac arrest (pCA). We examined the association between delayed timing of operation and postoperative outcomes following cardiac surgery in a large cohort of pCA.

Adults with a diagnosis of pCA undergoing a cardiac operation were identified in the 2016-2020 National Inpatient Sample. Those requiring surgery within 24 hours fo cardiac arrest were excluded. Patients who underwent a cardiac procedure after 5 days of cardiopulmonary resuscitation were classified as Delayed (others: Early). Multivariable regression models were constructed to evaluate associations between delayed timing of surgery with in-hospital mortality, postoperative complications, hospitalization duration, and costs.

Of an estimated 9,240 patients meeting study criteria, 4,860 (52.6%) received delayed cardiac surgery. Following entropy balancing, delayed surgery was significantly associated with decreased odds of in-hospital mortality (Adjusted Odds Ratio [AOR] 0.75, 95% Confidence Interval [CI] 0.58 – 0.97). However, delayed operation demonstrated greater odds of postoperative thromboembolic (AOR 1.44, 95% CI 1.02 – 2.04), and infectious (AOR 1.65, 95% CI 1.31 – 2.08) complications. Notably, delay did not alter odds of neurologic complication, and was linked to a decrement in per-day costs (β -$2,100, 95% CI -2,600 – −1,700).

While preoperative cardiac arrest remains challenging, the present study demonstrates the safety profile of delaying cardiac operation among patients tolerating at least 24 hours of a delay to surgery. Future studies are needed to elucidate the factors associated with favorable outcomes in this population.