Even Well-Treated Heart Failure May Raise Risk for Death After Noncardiac Surgery

February 19, 2019

Although the risk for death after noncardiac surgery is certainly elevated in patients with heart failure (HF) and a low left-ventricular ejection fraction (LVEF), the same applies when LVEF is only mildly reduced and even in HF with preserved ejection fraction (HFpEF).

Also, postoperative mortality is raised significantly in HF patients who are stable without symptoms, although not as sharply as in those with new-onset symptoms or chronic HF with recent decompensation.

Those observations from a retrospective Veterans Affairs cohort confirm that the risk for death in the 90 days after noncardiac surgery rises with HF severity, whether defined by symptoms or LVEF. But they also suggest that a preserved LVEF or being asymptomatic doesn't mean patients are off the hook for extra risk.

"You can be medically managed and doing quite fine, but our data are showing that you still have increased mortality," senior author Sherry M. Wren, MD, a surgeon at Stanford University School of Medicine, California, told theheart.org | Medscape Cardiology.

Cardiologists don't seem to fully appreciate the risks of noncardiac surgery in patients with heart failure, "except in the low-ejection-fraction, uncompensated group," she said.

"We were able to break it down by the four classes of ejection fraction, showing that even people with very well-preserved ejection fractions have a risk for mortality," said Wren. "It's like a dose-dependent risk. The higher your dose of heart failure, the more your risk."

Wren is senior author on the analysis, which was published in the February 12 issue of JAMA, with lead author Benjamin J. Lerman, MD, Stanford University School of Medicine.

Adjustment for complexity of surgery, comorbidities, including stage of any cancer, and other possible confounders "greatly attenuated the apparent risk of heart failure on postoperative mortality, suggesting that heart failure is a marker for a constellation of comorbidities that patients with heart failure tend to have, all of which contribute to the elevated risk," the authors note.

The findings underscore that HF patients, "especially those with symptoms or very low ejection fractions, should be counseled regarding their higher risk of postoperative surgical mortality," they write.

"Although optimizing their cardiac function should be pursued, all other associated modifiable risk factors that might contribute to postoperative mortality should also be optimized since heart failure by itself has a relatively small association with mortality."

Heart failure is well known to raise the risks associated with noncardiac surgery, but there has been little published on how the presence or absence of symptoms or the degree of LVEF affects that risk, observed Adrian F. Hernandez, MD, MHS, Duke University School of Medicine, Durham, North Carolina.

The current findings show that the common practice of reducing symptoms before the surgery doesn't remove the HF-related risk, he said in an interview.

"You do need to be attentive to this group of patients with heart failure, even if they are seemingly asymptomatic." In addition, HF symptoms can masquerade as the indication for noncardiac surgery and not be attributed to heart failure.

For example, "if they're having abdominal pain, it could be related to the heart failure, but it may be confused with other abdominal problems that are surgical," said Hernandez, who is not associated with the current study.

"We know that people need these procedures. What this doesn't tell us is that if you're higher risk, how do you mitigate that risk."

At the least, he said, "you would want to try to make sure they haven't been decompensated in the weeks before the procedure, and be sure to evaluate them closely both before and after the procedure."

The analysis involved 609,735 patient records from 2009 to 2016 included in the Veterans Affairs Surgical Quality Improvement Program that showed 1-year follow-up after noncardiac surgery.

Of the total, 7.9% involved patients with heart failure, defined as at least one hospital admission or at least two outpatient clinic visits with an HF diagnosis within 3 years of the surgery.

Mortality was significantly elevated in patients with heart failure overall, whether or not they were symptomatic. Heart failure with symptoms was defined in the report by American College of Surgeons criteria as newly diagnosed or chronic heart failure with signs or symptoms in the 30 days prior to surgery.

The 90-day mortality adjusted odds ratios (OR, 95% CI) compared with patients without HF were:

  • 1.67 (1.57 - 1.76) for all HF

  • 2.37 (2.14 - 2.63) for symptomatic HF

  • 1.53 (1.44 - 1.63) for asymptomatic HF

Wren pointed out that the HF cohort was medically well managed before surgery. "The vast majority of these patients were optimized; more than 90% of these patients were on a modern medication regimen with beta blockers and ACE inhibitors. Yet the risks are still there."

Adjusted Odds Ratio (OR) for 90-day Postoperative Mortality by LVEF Category* in Patients With and Without HF
LVEF Category Prevalence in Cohort, % Proportion Symptomatic, % OR (95% CI)
Preserved, ≥50% 59.9 9.9 1.51
(1.40–1.62)
Mildly reduced, 40%–49% 15.9 13.6 1.5
(1.38–1.71)
Moderately reduced, 30%–39% 12.6 17.1 1.85
(1.68–2.05)
Severely reduced, <30% 8.7 20.8 2.35
(2.092.63)
Adjusted for sex, race/ethnicity, age, body mass index, smoking, alcohol use, hypertension, atrial fibrillation, diabetes, CAD, history of stroke, asthma, COPD, peripheral vascular disease, disseminated cancer, surgical complexity, American Society of Anesthesiologists class, aortic stenosis, mitral regurgitation, pulmonary hypertension, VA facility, and preoperative creatinine and hematocrit levels.
*Limited to the 97% of the cohort with HF and available LVEF.

Of note, 90-day mortality was significantly elevated even in the subset of patients with asymptomatic HFpEF, with an adjusted OR of 1.46 (95% CI, 1.35 - 1.57).

Moreover, the contribution of heart failure to 90-day mortality declined with greater complexity of the noncardiac surgery procedure. "Heart failure absolutely confers risk at all degrees of surgery complexity," Wren observed. But owing to competing mortality risks, "when you look at highly complex procedures, heart failure contributes less to the attributable risk of death."

Adjusted OR for 90-day Postoperative Mortality Between Patients With and Without HF by Surgery Complexity
Complexity* OR (95% CI)
Standard 2.35 (2.15–2.58)
Intermediate 1.79 (1.65–1.92)
Complex 1.29 (1.02–1.63)
Adjusted for sex, race/ethnicity, age, body mass index, smoking, alcohol use, hypertension, atrial fibrillation, diabetes, CAD, history of stroke, asthma, COPD, peripheral vascular disease, disseminated cancer, surgical complexity, American Society of Anesthesiologists class, aortic stenosis, mitral regurgitation, pulmonary hypertension, VA facility, and preoperative creatinine and hematocrit levels.
*Defined by VA Surgical Complexity Matrix.

"In contrast to previous studies, this analysis provides a more detailed description of the associations of increasing levels of systolic dysfunction and the presence or absence of heart failure symptoms with surgical outcomes than previously documented," agreed a linked editorial in JAMA Surgery.

Among its limitations is that women make up less than 10% of the Veterans Affairs cohort, writes John S. Ikonomidis, MD, PhD, University of North Carolina at Chapel Hill.

However, "the data reported here is highly valuable and comprehensive information that practitioners can use for preoperative planning and also in discussions with patients."

Wren and Lerman reported no conflicts. Hernandez has disclosed research support from Aires Pharmaceuticals, Amgen, Amylin Pharmaceuticals, AstraZeneca, Bristol-Myers Squibb, Daiichi-Sankyo, GlaxoSmithKline, Luitpold Pharmaceuticals, Merck, and Novartis; consulting or other services for Amgen, AstraZeneca, Bayer, Boehringer Ingleheim, Boston Scientific, MyoKardia, Novartis, Sanofi-Aventis, and Pluristem Therapeutics; and receiving honoraria from Bayer, Boston Scientific, and Novartis. Ikonomidis reported no conflicts.

JAMA. 2019;321:572-579. Abstract

JAMA Surgery. Published online February 12. Editorial

Follow Steve Stiles on Twitter: @SteveStiles2. For more from theheart.org | Medscape Cardiology, follow us on Twitter and Facebook.

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