Original Title: Hemodynamic Assessment of Aortic Regurgitation after Transcatheter Aortic Valve Replacement – The Diastolic Pressure-Time Index.
Reference: Robert Höllriegel et al. JACC Cardiovasc Interv. 2016 Apr 16.
Courtesy of Dr. Agustín Vecchia.
In 2012 Sinning and collaborators presented a study in the “Journal of the American College of Cardiology” about an index to hemodynamically assess the magnitude of aortic regurgitation (AR) post transcatheter aortic valve replacement (TAVR) and the prognostic capacity of this index. Calculating this index involved the following: the difference between diastolic aortic pressure and left ventricular end-diastolic pressure over systolic pressure [(DP – LVEDP) / SP] x 100.
In the study, published by Höllriegel and collaborators, the authors suggest that the index used by Sinning is affected by the fact that due to HIV, which nearly always accompany these patients, LVEDP is normally increased, which results in a low index in absence of significant AR.
Based on this, they propose a new index using area under the LV pressure-time curve.
The present study included 362 patients undergoing transfemoral TAVR (Corevalve or Sapien) in one single center. To calculate the diastolic pressure-time (DPT) index, they used the aortic and left ventricular pressure-time curves obtained during the first 5 minutes after valve implantation. The area between the aortic and left ventricular pressure-time curves was divided by the duration of diastole and adjusted to systolic arterial blood pressure [DPT index adj = (DPT index/systolic blood pressure) x 100].
Patients with non-relevant AR (grade <2) had higher adjusted DPT index (30.7 ± 6.8) than those with relevant AR (grade ≥ 2) showing a lower DPT (26.2 ± 5.8; p < 0.05). Those patients with adjusted DPT ≤ 27.9 had significantly higher mortality at one year than those with values higher than 27.9 (41.4% vs 13.5%; HR: 3.8; CI 95% CI 2.4 to 5.9; p<0.001). In multivariable analysis, adjusted DPT was the most important independent predictor of mortality at one year (hazard ratio: 2.5; 95% CI: 1.8 to 3.7; p < 0.001).
Editorial Comment:
Höllriegel and collaborators propose a new index in the following study, one incorporating the differential area under the curve of aortic diastolic pressure/ left ventricular pressure, suggesting this seems to have better prognostic value than other indexes such us the originally published by Sinning. The fact that, given left ventricular hypertrophy many patients with mild post TAVR AR have elevated LVEDP leads, according to these authors, to overestimate AR as indicated by the original Sinning index, which hindered mortality prediction at one year in this study, fact that contrasted with the predictive value of the new index, which would be less dependent on LVEDP and independent of cardiac frequency, reflected in the hemodynamic state during diastole, not just the end of it.
Even though the theory and validation of these patients seem to prove researchers right, it is also true that this index is more complex than the one proposed by Sinning, which should be taken into account in the daily practice.
Courtesy of Dr. Agustín Vecchia. German Hospital, Buenos Aires, Argentina.
