麻豆传媒

A novel scoring system based on comorbidity, frailty, and disability factors predicted the odds of death after transcatheter aortic valve replacement (TAVR), researchers reported.

Under a system giving 2 points for home oxygen use, albumin level below 3.3 g/dL, and assisted living and 1 for age over 85, patients with a score of at least 3 points had a 30-day death risk of 10.9% compared with 3.6% among those with 0 points.

A scoring system based on home oxygen use (2 points), albumin level below 3.3 g/dL (1 point), falls in past 6 months (1 point), Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM) score over 7% (1 point), and an high Charlson comorbidity score (1 point) predicted 1-year mortality (12.3% for up to 1 point versus 36.6% for 4 points or higher).

The 1-year mortality model had a slightly better C-statistic of 0.79 (95% CI 0.59-0.95) than that of the 30-day one (0.75, 95% CI 0.35-1.04), according to the study by , of St. Vincent's Heart Center of Indiana in Indianapolis, and colleagues in the .

Nevertheless, "the C-statistic for both the derivation subset and the validation subset showed good discrimination for the model, a finding suggesting a moderately high predictive ability," they argued. "Many of these predictors are not found in conventional surgical risk assessments, such as STS PROM."

"This simple scoring system may facilitate identifying particularly high-risk patients who may require more intensive screening by the heart team."

"What is unique about this risk prediction algorithm is that in addition to the usual variables predictive of death, assessments of frailty and disability were also used," , and , both of the Heart Hospital Plano, Texas.

In an accompanying editorial, the pair weighed the utility of a single score for TAVR risk.

"It is clear that a single unified scale or scoring system cannot adequately predict both operative risk and long-term risk in an older patient with a complex clinical situation and aortic valve stenosis," they wrote, although the study "highlights the need to incorporate current risk scores such as the STS PROM with frailty to predict short-term and long-term risk of death adequately."

"Given the time commitment required to complete the comorbidity calculation, frailty testing, and disability scoring in the CoreValve trial, clearly clinicians will need a unified, efficient means of evaluation," Mack and Holper concluded.

Hermiller's study analyzed high-risk patients from the CoreValve U.S. pivotal trial who had severe aortic stenosis and were considered to be at high surgical risk. The predictive model was created from a derivation group of 2,482 participants and a validation group of 1,205.

Overall death rates at 30 days and 1 year were 5.8% and 22.8%, respectively.

Following multivariable adjusting, the investigators found that independent predictors of 30-day mortality were:

• Home oxygen use (hazard ratio [HR] 1.74, 95% CI 1.16-2.61)
• Assisted living (HR 1.68, 95% CI 1.05-2.69)
• Albumin levels below 3.3 g/dL (HR 1.60, 95% CI 1.04-2.47)
• Age over 85 years (HR 1.46, 95% CI 0.99-2.15)

The risk factors for 1-year mortality after TAVR were:

• Home oxygen use (HR 1.90, 95% CI 1.47-2.44)
• Albumin levels below 3.3 g/dL (HR 1.40, 95% CI 1.04-1.91)
• Falls in the past 6 months (HR 1.36, 95% CI 1.03-1.81)
• STS PROM score above 7% (HR 1.36, 95% CI 1.05-1.77)
• Severe Charlson comorbidity score (HR 1.27, 95% CI 0.98-1.65)

"This predictive model may not apply to modest-risk or lower-risk patients," acknowledged Hermiller's group. "We also acknowledge that our scoring system would be limited in practical terms by whether or not such detailed information on baseline frailties and disabilities is collected in other studies or in routine clinical practice."