Impact of Prosthetic Valve Regurgitation Assessed by Echocardiography and Magnetic Resonance Imaging on Long-Term Clinical Outcomes after TAVR.

BACKGROUND: Prosthetic valve regurgitation (PVR) impairs early and mid-term outcomes after transcatheter aortic valve replacement (TAVR). We explored the impact of PVR assessed by transthoracic echocardiography (TTE) and magnetic resonance imaging-regurgitation fraction (MRI-RF) on long-term clinical outcomes. METHODS: PVR was assessed by TTE applying the Valve Academic Research Consortium criteria and MRI-RF (from velocity-encoded phase contrast magnetic resonance sequence) in 424 patients. RESULTS: MRI-RF correlated modestly with the echocardiographic grades of PVR (Spearman's rank correlation coefficient = 0.32, p < 0.001). Using an MRI-RF ≥20% to define ≥ moderate PVR, echocardiography and MRI-RF agreed on PVR classification in 412 patients (97.2%; kappa statistic = 0.56, p < 0.001). Five-year mortality or reintervention was higher in patients with echocardiographic ≥ moderate PVR (83.3% vs. 45.0%, log rank p value = 0.002; HR [95% CI]: 3.18 [1.48-6.84]) as well as in patients with MRI-RF ≥20% (79.3% vs. 43.2%, log rank p value <0.001; HR [95% CI]: 2.68 [1.53-4.70]), while the outcomes of patients with echocardiographic mild PVR were not significantly different from those with none-trace PVR. In the two latter groups (echocardiographic < moderate PVR), MRI-RF ≥20% was associated with a significantly higher 5-year mortality or reintervention as compared with MRI-RF <20% (79.5% vs. 42.2%, log rank p value = 0.023; HR [95% CI]: 2.26 [1.10-4.65]). CONCLUSIONS: Greater than mild PVR as defined by TTE or MRI-RF is associated with impaired long-term clinical outcomes after TAVR. MRI-RF can be used to further risk-stratify patients with echocardiographic less-than-moderate PVR.

Hemodynamic performance of the balloon-expandable SAPIEN 3 valve as assessed by cardiac magnetic resonance.

BACKGROUND: Scarce data exist on transcatheter heart valve (THV) performance evaluated by cardiac magnetic resonance (CMR) in newer generation THV patients. Furthermore, it has been suggested that echocardiographic evaluation after TAVR may inaccurately assess residual AR in some patients. This study aimed to determine the incidence and severity of aortic regurgitation (AR) assessed by CMR in patients undergoing TAVR with the SAPIEN 3 valve, and evaluate the agreement between CMR and transthoracic echocardiography (TTE) on the assessment of AR severity in such patients. METHODS: This multicentric observational study included 146 SAPIEN 3 patients with TTE and CMR within the month following their procedure. According to the CMR regurgitation fraction (RF), AR was considered mild and moderate-severe if the RF was 15-<30% and ≥ 30%, respectively. TTE exams followed VARC-2 recommendations. RESULTS: By CMR, SAPIEN 3 recipients displayed a mean RF of 5.0 ± 6.1%, and mild and moderate-severe AR rates of 3.4% and 0.7%, respectively. The agreement between CMR-TTE was modest (weighted κ = 0.2640, p<0.001), due to an overestimation of AR severity by TTE. A historical cohort of 139 SAPIEN XT patients with a post-procedure CMR, displayed a mean RF of 9.6 ± 10.7% and mild and moderate-severe AR rates of 18.7% and 3.6%, respectively (p < .001 vs. SAPIEN 3 group). CONCLUSIONS: SAPIEN 3 recipients exhibited very low rates of residual AR by CMR, suggesting a surgical-like performance regarding AR with this newer generation THV. TTE tended to overestimate the severity of AR, particularly among mild AR patients.

Effect of Aortic Regurgitation by Cardiovascular Magnetic Resonance After Transcatheter Aortic Valve Implantation.

Cardiovascular magnetic resonance (CMR) has demonstrated a high accuracy for evaluating the severity of aortic regurgitation (AR). However, scarce data exist on the impact of AR as evaluated by CMR on clinical outcomes following transcatheter aortic valve implantation (TAVI). The objective of this study was to evaluate the impact of AR as determined by CMR on clinical outcomes (mortality, heart failure [HF] hospitalization) post-TAVI. A total of 448 TAVI recipients from 2 centers (mean age: 80 ± 7 years, mean STS: 5.8 ± 5.4%) who survived the periprocedural period with no pacemaker implantation were included. A newer generation transcatheter valve system was used in 213 patients (48%). The CMR examination was performed at a median of 12 (IQR: 7 to 21) days post-TAVI. After a mean follow-up of 24 ± 19 months, a total of 94 patients (21%) had died and 72 patients (16%) had at least 1 hospitalization because of decompensated HF. The aortic regurgitation fraction (RF) as determined by CMR was an independent predictor of mortality (hazard ratio[HR]:1.06 for each increase of 10%, 95% confidence interval [CI]: 1.01 to 1.12, p = 0.03) and HF hospitalization (HR:1.15 for each increase of 10%, 95% CI:1.02 to 1.30, p = 0.02). The rate of moderate-severe CMR-AR defined as a RF ≥30% was 3%, and this was associated with an increased risk of mortality (HR: 2.63, 95% CI: 2.30 to 2.99, p <0.001) and HF hospitalization (HR: 2.96, 95% CI: 1.62 to 5.42, p ˂0.001). A stepwise increase in the risk of mortality and HF hospitalization was observed with an increase in AR severity, with a peak increase among patients with RF ≥30%. In conclusion, our results showed the clinical usefulness of evaluating AR severity by CMR post-TAVI. CMR would be particularly helpful in doubtful cases or those with discordances between echocardiography and clinical data.

Aortic regurgitation and left ventricular remodeling after transcatheter aortic valve implantation: a serial cardiac magnetic resonance imaging study.

BACKGROUND: Aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) has been associated with poor outcomes, but little is known about how it evolves over time. We evaluated left ventricular (LV) function, remodeling, and the occurrence and evolution of AR after TAVI by using cardiac MRI. METHODS AND RESULTS: Forty-three patients treated with transfemoral TAVI underwent cardiac MRI 1 week and 6 months after TAVI. LV volumes and function were assessed by using standard cine MRI sequences. Phase-contrast imaging was performed to quantify the degree of AR. The mean age of the evaluated patients was 80 years, and 65% of patients were women. At baseline MRI, the median LV ejection fraction was 58.1%, which improved significantly at follow-up to 63.4% (P<0.0001). A significant reduction of LV end-diastolic volume (149.7 ± 41.4-140.1 ± 43.9 mL; P=0.014) and of LV mass (156.3 ± 32.8-142.7 ± 39.3 g; P<0.001) was observed. Over time, aortic regurgitant fraction increased slightly but significantly from 5.2% to 7.8% (P=0.04). Subgroup analysis revealed that significant changes of LV ejection fraction, volumes, and mass only occurred in patients with no or mild AR at baseline MRI, whereas those parameters remained unchanged in patients with AR more than or equal to grade II. CONCLUSIONS: By using cardiac MRI in patients with TAVI, a significant improvement of LV function, volume, and mass can be documented. Mild-to-moderate AR is commonly seen, and AR shows a small increase over time. More-than-mild AR seems to prevent LV functional and structural recovery after TAVI.

Haemodynamic evaluation of aortic regurgitation after transcatheter aortic valve implantation using cardiovascular magnetic resonance.

AIMS: Echocardiography may underestimate the degree of paravalvular aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve bioprosthesis due to inherent limitations of ultrasound imaging in the evaluation of implanted cardiac prostheses. We aimed to evaluate the accuracy and feasibility of cardiovascular magnetic resonance (CMR) in quantifying regurgitant volume (RV) and regurgitant fraction (RF) in patients treated with this bioprosthesis for severe calcific aortic stenosis, and to compare the results with echocardiography and aortography. METHODS AND RESULTS: This study included 16 patients with a mean age of 78.7 years (eight women, eight men) who underwent successful TAVI using Medtronic CoreValve bioprosthesis. AR was evaluated by CMR, echocardiography, and aortography. Angiography was performed immediately after valve implantation. CMR and echocardiography were performed four weeks after valve implantation. There was a highly significant correlation between the CMR-derived and the angiographically-estimated degree of AR (r=0.86, p<0.001). On the other hand, there was only a limited correlation between CMR and echocardiography (r=0.374, p=0.15) as well as angiography and echocardiography (r=0.319, p=0.23) regarding the degree of AR. The weighted kappa for agreement between echocardiography and angiography was 0.14, for agreement between echocardiography and CMR 0.20, and for agreement between angiography and CMR 0.72. Echocardiography underestimated AR by one degree compared to CMR in five patients and 2 degrees in two patients; in six of these, the degree of AR obtained by CMR was similar to angiography. CONCLUSIONS: In patients undergoing TAVI, comparisons between purely quantitative measurements of AR by CMR and qualitative assessment by angiography showed better correlations than those with echocardiography. This suggests that echocardiography may underestimate the degree of AR and CMR in these circumstances has a great potential in reliably measuring the severity of AR in a quantitative manner.