Echocardiographic determinants of LV functional improvement after transcatheter aortic valve replacement

Application of echocardiography in transcatheter aortic valve replacement in patients with severe aortic regurgitation and correlation analysis of postprocedural complications

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is gradually becoming an alternative therapy for patients who cannot adapt to surgical treatment or have contraindications.

OBJECTIVES

The purpose of this study was to investigate the value of echocardiography in the evaluation of severe AR patients treated with TAVR and to analyze the correlations with postprocedural complications to improve the evaluation and screening of patients.

METHODS

We retrospectively analyzed clinical and echocardiographic data of 70 patients with severe AR. Periaortic valve structures were carefully measured by esophageal echocardiography (TEE) and compared with the multilayer slice computed tomography (MSCT) findings. Real-time three-dimensional esophageal echocardiography (RT-3D TEE) was monitored during the operation, and a 30-day postprocedural follow-up was performed. The relationship between postprocedural complications and patients' clinical data or periaortic valve structures was analyzed by multifactorial analysis to identify relevant predictors of complications.

RESULTS

The TEE measurements of periaortic valve structures were in good agreement with the MSCT measurements. Among the patients who underwent successful operations, both left atrial (LA) and left ventricular (LV) diameters were reduced, and the left ventricular ejection fraction (LVEF) was improved 30 days after TAVR compared with the preprocedural period (P < .05). Permanent pacemakers were implanted in 15 patients. The presence of preprocedural right bundle branch block (RBBB) (OR: 2.93; 95% CI: 1.18-12.70; P = .01) was an independent factor for permanent pacemaker implantation after TAVR.

CONCLUSIONS

Echocardiography plays an extremely important role in TAVR procedures. The presence of preprocedural RBBB can be an independent predictor of postprocedural pacemaker implantation.

Acute haemodynamic impact of transcatheter aortic valve implantation in patients with severe aortic stenosis

Aims

There are limited data about the intraprocedural haemodynamic study performed immediately before and after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis (AS). We aimed to evaluate the acute haemodynamic impact of TAVI in patients with severe AS and to investigate invasive and non‐invasive parameters predicting all‐cause mortality.

Methods and results

A total of 245 consecutive AS patients (43% male, mean age 80.3 ± 7.3 years) undergoing TAVI were enrolled. Intraprocedural left heart catheterization (LHC) and echocardiogram before and after TAVI were performed. The clinical endpoint was the death for any cause. LHC after TAVI revealed significant changes in aortic and left ventricular (LV) pressures, including indexes of intrinsic myocardial contractility and diastolic function such as positive dP/dT (1128.9 ± 398.7 vs. 806.3 ± 247.2 mmHg/s, P ˂ 0.001) and negative dP/dT (1310.7 ± 431.1 vs. 1075.1 ± 440.8 mmHg/s, P ˂ 0.001). Post‐TAVI echo showed a significant reduction in LV end‐diastolic (P = 0.036) and end‐systolic (P ˂ 0.001) diameters, improvement in LV ejection fraction (from 55 ± 12% to 57.2 ± 10.5%, P ˂ 0.001), and pulmonary artery systolic pressure (42.1 ± 14.2 vs. 33.1 ± 10.7 mmHg, P < 0.001). After a mean follow‐up time interval of 24 months, 47 patients died. Post‐TAVI significant aortic regurgitation at echocardiography was the only independent predictor of mortality (hazard ratio 5.592, confidence interval 1.932–16.184, P = 0.002).

Conclusions

Left heart catheterization performed immediately before and after prosthesis release offers a unique insight in the assessment of LV adaptation to severe AS and the impact of TAVI on LV, catching changes in indexes of intrinsic contractility and myocardial relaxation. Aortic regurgitation assessed by echocardiography was the only independent predictor of mortality in patients undergoing TAVI.

Prognostic impact of postprocedure stroke volume in patients with low-gradient aortic stenosis

Objective

The effect of postoperative blood flow status on the prognosis of patients with low-gradient severe aortic stenosis (AS) has not been examined. Severe AS is associated with a higher mortality rate after transcatheter aortic valve implantation (TAVI). We examined the prognostic value of low-flow status by comparing stroke volume indices (SVi) before and after TAVI in patients with symptomatic, low-gradient severe AS.

Methods

A total of 1613 patients with severe symptomatic AS who underwent TAVI in 14 Japanese institutes for low-gradient severe AS (418 patients, median age 84 years, 32.5% men) were prospectively enrolled. The primary endpoint was cardiovascular mortality during follow-up after TAVI, and independent predictors were evaluated. Receiver operating characteristic curves were generated to determine the optimal cut-off value of post-TAVI SVi for predicting cardiovascular mortality, and the receiver operating characteristic curves of pre-TAVI and post-TAVI SVi were compared.

Results

The cardiovascular mortality rate was 4.1% (17 patients) during follow-up (median 9.2 months). Multivariate analysis revealed post-TAVI SVi to be an independent predictor of cardiovascular mortality (per 10 mL/m² decrease; HR, 2.0; 95% CI 1.28 to 3.12). The optimal cut-off value of post-TAVI SVi was 41.4 mL/m². Post-TAVI SVi showed significantly larger area under the curve than pre-TAVI SVi (0.74 (95% CI 0.69 to 0.79) vs 0.61 (95% CI 0.56 to 0.65), p<0.05).

Conclusions

Post-TAVI SVi is a better predictor of cardiovascular mortality than pre-TAVI SVi in patients with symptomatic low-gradient severe AS. Low-flow and low-normal-flow status (35≤ SVi <40 mL/m²) require careful management after TAVI.

Role of contractile reserve as a predictor of mortality in low-flow, low-gradient severe aortic stenosis following transcatheter aortic valve replacement

OBJECTIVES

The aim of this study was to determine the prognostic value of contractile reserve (CR) at baseline in patients with low-flow, low-gradient severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR).

BACKGROUND

Patients with severe AS, left ventricular dysfunction, and low transaortic gradient are at high risk for mortality during surgical aortic valve replacement (SAVR). Furthermore, patients without CR have been shown to have perioperative mortality comparable to that of patients treated medically for severe AS.

METHODS

We retrospectively analyzed patients who underwent TAVR with a diagnosis of low-gradient severe AS (mean transvalvular aortic gradient < 40 mmHg, LVEF < 50%, and AVA ≤ 1.0 cm² or AVAi ≤ 0.6 cm² ) and who had a pre-TAVR dobutamine stress echocardiogram (DSE). Patients were stratified by the presence or absence of CR, defined as an increase in stroke volume ≥ 20% during DSE.

RESULTS

From 2008 to 2016, 61 patients with low-gradient severe AS underwent TAVR and had pre-TAVR DSE. CR was present in 31 patients (51%) and absent in 30 (49%). There was no significant difference between the two groups in baseline demographics, medical history, access site, or types of valves. All-cause mortality was similar in both groups at 30 days (13% with CR vs 10% without CR, P = 1.00) and 1 year (29% with CR vs 33% without CR, HR 1.20, 95% CI 0.49-2.96, P = 0.69).

CONCLUSION

In patients with low-flow, low-gradient severe AS undergoing TAVR, the presence or absence of CR does not predict all-cause mortality at 30 days or 1 year.

Long term outcomes of transcatheter aortic valve implantation (TAVI): a systematic review of 5-year survival and beyond

BACKGROUND

Transcatheter aortic valve implantation/replacement (TAVI/TAVR) is becoming more frequently used to treat aortic stenosis (AS), with increasing push for the procedure in lower risk patients. Numerous randomized controlled trials have demonstrated that TAVI offers a suitable alternative to the current gold standard of surgical aortic valve replacement (SAVR) in terms of short-term outcomes. The present review evaluates long-term outcomes following TAVI procedures.

METHODS

Literature search using three electronic databases was performed up to June 2017. Studies which included 20 or more patients undergoing TAVI procedures, either as a stand-alone or concomitant procedure and with a follow-up of at least 5 years, were included in the present review. Literature search and data extraction were performed by two independent researchers. Digitized survival data were extracted from Kaplan-Meier curves in order to re-create the original patient data using an iterative algorithm and subsequently aggregated for analysis.

RESULTS

Thirty-one studies were included in the present analysis, with a total of 13,857 patients. Two studies were national registries, eight were multi-institutional collaborations and the remainder were institutional series. Overall, 45.7% of patients were male, with mean age of 81.5±7.0 years. Where reported, the mean Logistic EuroSCORE (LES) was 22.1±13.7 and the mean Society of Thoracic Surgeons (STS) score was 9.2±6.6. The pooled analysis found 30-day mortality, cerebrovascular accidents, acute kidney injury (AKI) and requirement for permanent pacemaker (PPM) implantation to be 8.4%, 2.8%, 14.4%, and 13.4%, respectively. Aggregated survival at 1-, 2-, 3-, 5- and 7-year were 83%, 75%, 65%, 48% and 28%, respectively.

CONCLUSIONS

The present systematic review identified acceptable long-term survival results for TAVI procedures in an elderly population. Extended follow-up is required to assess long-term outcomes following TAVI, particularly before its application is extended into wider population groups.