麻豆传媒

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Patients with diabetes who had aortic stenosis fared better in terms of mortality and kidney function during the first year if they underwent transcatheter aortic valve implantation (TAVI) rather than surgery, a post-hoc analysis found.

All-cause mortality at 1 year was 18% among diabetic patients treated with TAVI compared with 27.4% of those treated surgically, for a hazard ratio of 0.60 (95% CI 0.36-0.99, P=0.04), according to , of Washington University School of Medicine in St. Louis, and colleagues.

Patients who received the transcatheter treatment also had lower rates of renal failure necessitating dialysis (4.2% versus 10.6%, P=0.05), and requiring dialysis for longer than a month (0% versus 6.1%, P=0.003), the researchers reported on Nov. 27 in the Journal of the American College of Cardiology.

The findings of this study have "important clinical implications for the treatment of patients with severe [aortic stenosis] and diabetes at high risk for surgery," Lindman and colleagues observed.

The presence of diabetes has adverse effects on morbidity and mortality in cardiovascular disease, and, in patients with aortic stenosis, can worsen left ventricular function and heart failure and can increase hypertrophic remodeling.

Diabetes has also been associated with poor outcomes after surgical aortic valve replacement. The reasons for this increased risk are not fully understood, but may involve oxidative stress, inflammation, and reperfusion injury, the researchers explained.

"As such, a less invasive method of valve replacement that avoids the injurious effects of cardiopulmonary bypass may lead to improved clinical outcomes among these high-risk patients with diabetes," they wrote.

To compare the outcomes of less traumatic TAVI with surgery, they conducted a subgroup analysis of , which included 657 patients.

For this analysis, they focused on the 275 patients who had diabetes, 145 who had the TAVI treatment, and 130 who were treated surgically.

Stroke incidence, during the first year, was the same in the two groups, at 3.5%.

The authors reported a significant interaction between diabetes and treatment group for 1-year all-cause mortality (P=0.048), but no significant difference in all-cause mortality at 1 year (P=0.48) among nondiabetic patients.

While TAVI showed a benefit in the first year, the difference in mortality was no longer present after 2 years, Joachim Schofer, MD, of Hamburg University Cardiovascular Center in Germany, noted in an accompanying editorial.

This might reflect patients' comorbidities or the long-term effect of TAVI, which has been associated with aortic regurgitation, according to Schofer.

This is the first study to report improved outcome with TAVI versus surgical therapy of severe aortic stenosis in diabetic, high-risk patients, and "raises the intriguing possibility that transcatheter valve replacement may be the preferred approach" for these patients, Lindman and colleagues wrote.

The improved outcomes with TAVI may relate to a lower systemic inflammatory response than can occur with the surgical approach.

"Consistent with this possibility, the 24-hour post-procedure blood analyses drawn in the PARTNER trial showed higher levels of white blood cells in patients with diabetes after surgery compared to transcatheter valve replacement," they said.

The authors did note some limitations in their trial. "Diabetes status was not a prespecified subgroup analysis and, as such, these results should be considered hypothesis generating and need to be confirmed in future studies," they said.

In addition, diabetes diagnoses were determined by the enrolling sites and not verified in other ways. And the authors did not have information on duration of diabetes, anti-diabetes medication use, or glucose levels.

"How each of these factors contributes to the treatment effect of transcatheter versus surgical aortic valve replacement will require further study," the authors wrote.