After transcatheter aortic valve replacement (TAVR, also known as TAVI), hemodynamic characterization of any persistent aortic regurgitation with a novel index beats the Aortic Regurgitation Index for predicting survival, a single-center study showed.
Patients with DPT-Indexadj scores of 27.9 and below were at higher risk for death at 1 year (41.4% versus 13.5%, hazard ratio 3.8, 95% CI 2.4-5.9). That 27.9 threshold remained a strong predictor of mortality after multivariable adjustment (HR 2.5, 95% CI 1.8-3.7).
That novel score is calculated by measuring the area between the aortic and left ventricular pressure-time curves during diastole, divided by the duration of diastole, and then further adjusted for systolic blood pressure, Robert Höllriegel, MD, of Germany’s University of Leipzig, and colleagues reported online in JACC: Cardiovascular Interventions.
The Aortic Regurgitation Index, however, failed to predict 1-year mortality in the analysis.
“The DPT-Indexadj is a simple, investigator-independent parameter that should be considered to differentiate between relevant and non-relevant aortic regurgitation after TAVI,” the authors concluded.
“Hemodynamic parameters might be useful to identify patients with increased aortic regurgitation-related risk and to guide intraprocedural decision making, especially in patients with aortic regurgitation of borderline significance. Those parameters are reproducible, investigator-independent, easy and fast to quantify, and can be measured at different points of time, especially if balloon postdilatation is performed to reduce aortic regurgitation.”
The authors suggested that the Aortic Regurgitation Index, by estimating the incidence of aortic regurgitation based on left ventricular end-diastolic pressure (LVEDP), may have failed because even patients without aortic regurgitation can have elevated LVEDP.
“In contrast, our new DPT-Indexadj is less dependent on LVEDP, independent of the heart rate and reflects hemodynamics during complete diastole. In this retrospective study, the DPT-Indexadj was the more effective hemodynamic parameter to differentiate between relevant and non-relevant aortic regurgitation in comparison to the Aortic Regurgitation Index,” they concluded.
But Jan-Malte Sinning, MD, of University Hospital Bonn in Germany, suggested that the DAPT-Indexadj isn’t perfect either.
Sinning helped develop the original Aortic Regurgitation Index. Since then, he wrote in an accompanying editorial, “several studies have tried to increase its accuracy. All of these studies might be difficult to compare, because paravalvular regurgitation was assessed by different modalities and classification schemes in a non-standardized fashion.”
“If we really want to find the golden formula for paravalvular regurgitation assessment, future larger studies are needed, especially now that (fortunately!) significant paravalvular regurgitation has become a rare event with the introduction of repositionable, next-generation transcatheter heart valves with additional peri-prosthetic sealing mechanisms,” he added. “Until this golden formula is found, we have to ask ourselves whether “less is more” and to decide whether a simple, easy-to-calculate formula might complement our angiographic or echocardiographic paravalvular regurgitation grading algorithm to identify patients with suboptimal results and negative outcomes.”
Höllriegel’s retrospective analysis included 362 consecutive patients with severe aortic stenosis.
Besides being a single-center retrospective analysis, the investigation had another major limitation: “In our hospital all TAVI procedures are performed under local anaesthesia, and without transesophageal echocardiography. Therefore, we cannot provide any echocardiographic data for evaluation of aortic regurgitation during the procedure. The advantage of the DPT-Indexadj over the Aortic Regurgitation Index is maybe overstated,” Höllriegel and colleagues cautioned.
Sinning acknowledged that “a false-positive Aortic Regurgitation Index can be seen with abnormal ventricular or aortic compliance.”
“Studies to date suggest intra-procedural decision-making using hemodynamic parameters should always integrate hemodynamics with other imaging modalities, such as echocardiography and angiography,” he wrote.
Höllriegel disclosed no relevant conflicts of interest.
Sinning reported receiving speaker honoraria and research grants from Medtronic, Edwards Lifesciences, Direct Flow Medical, and Boston Scientific.
JACC: Cardiovascular Interventions
Höllriegel R, et al “Hemodynamic assessment of aortic regurgitation after transcatheter aortic valve implantation: the diastolic pressure time index” JACC Cardiovasc Interv 2016; DOI: 10.1016/j.jcin.2016.02.012.
JACC: Cardiovascular Interventions
Sinning J “Searching for the golden formula — less is more, or not?” JACC Cardiovasc Interv 2016; DOI: 10.1016/j.jcin.2016.03.021.