Outcomes of Surgical Aortic Valve Replacement: The Benchmark for Percutaneous Therapies

Comparison of transcatheter and surgical aortic valve replacement long-term outcomes: a retrospective cohort study with overlap propensity score weighting

BACKGROUND AND AIMS

Randomised controlled trials comparing transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) were performed in highly selected populations and data regarding long-term secondary complications beyond mortality are scarce. This study used data from Ontario, Canada to compare mid-term and long-term clinical outcomes in a representative real-world cohort of patients who underwent TAVR and SAVR from 2007 to 2016.

METHODS

A novel overlap weighting propensity score method was used to match patients undergoing TAVR or SAVR. Primary outcomes were all-cause, cardiovascular and non-cardiovascular mortality either in-hospital or at 1, 3 and 5 years postdischarge. Secondary outcomes included adverse outcomes and readmission. Long-term primary and secondary outcomes were compared using a weighted competing risks subdistribution proportional hazards model.

RESULTS

The study included 9355 SAVR and 2641 TAVR patients. All-cause mortality at 1 year (HR 1.21; 95% CI 1.02 to 1.43), 3 years (HR 1.45; 95% CI 1.28 to 1.64) and 5 years (HR 1.48; 95% CI 1.33 to 1.65) was significantly higher among patients underwent TAVR compared with SAVR, with both cardiovascular mortality at 3 and 5 years and non-cardiovascular mortality at 1, 3 and 5 years significantly higher for TAVR. Hazards of myocardial infarction and readmission for angina at 1, 3 and 5 years were significantly greater for TAVR.

CONCLUSIONS

In this overlap weighted cohort, both cardiac and non-cardiac mortality rates were increased in TAVR patients. Residual or unmeasured confounding may have contributed to these findings. More studies are needed to identify factors predictive of long-term outcomes in real-world cohorts.

New Model for the Assessment of Transcatheter Aortic Valve Replacement Devices in Sheep

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is an effective therapy in treating high-risk patients suffering from aortic stenosis. Animal models used to evaluate safety and efficacy of TAVR devices prior to clinical use lack a stenotic aortic annulus, a critical impediment to long-term TAVR device evaluation. We sought to create a reproducible model of aortic stenosis using a modified aortic annuloplasty (MAA) procedure in sheep, followed by deployment and long-term evaluation of TAVR devices using this model.

METHODS

Twelve sheep underwent the MAA procedure and were recovered. Transthoracic echocardiography (TTE) was used to monitor changes in the aortic annulus in the postoperative period. At 60 days post-MAA, Test group animals were anesthetized for TAVR insertion and Control animals underwent a necropsy. Test animals were recovered following TAVR insertion and observed for a postoperative period of 140 days.

RESULTS

Twelve sheep survived the annuloplasty procedure and the 60-day recovery period. Gross examination of seven Control group animals revealed the implanted annuloplasty ring segments formed hard protrusions into the aortic annulus. Five sheep in the Test group underwent successful deployment of Abbott's experimental TAVR device without evidence of migration. Examination at 140 days post-TAVR insertion showed all devices tightly anchored within the modified aortic annulus.

CONCLUSIONS

The MAA procedure creates stenotic segments in the aortic annulus with adequate rigidity for anchorage and long-term evaluation of TAVR devices. This represents the first model that successfully mimics human aortic stenosis and provides a clinically relevant TAVR deployment platform for long-term evaluation in sheep.

Transcatheter aortic valve implantation with balloon-expandable valve: early experience from China

Objective

The aim of the current study was to evaluate the early experience of the application of transcatheter aortic valve implantation with the balloon-expandable system in China. The transcatheter aortic valve implantation technology has been widely used for patients with inoperable severe aortic stenosis in the developed world. The application of transcatheter aortic valve implantation is still in the early stages of testing in China, particularly for the balloon-expandable valve procedure.

Methods

This was a retrospective study. All patients undergoing transcatheter aortic valve implantation with balloon-expandable system in our hospital between 2011 and 2014 were included. Edwards SAPIEN XT Transcatheter Heart Valve was used. The improvement of valve and heart function was evaluated as well as 30-day mortality and major complications according to the VARC-2 definition.

Results

A total of 10 transcatheter aortic valve implantation procedures with the balloon-expandable system were performed in our hospital, of which 9 were transfemoral and 1 was transapical. The median age was 76 years, and the median STS score and Logistic EuroSCORE (%) were 8.9 and 16.2. The implantation was successfully conducted in all patients, only 2 patients had mild paravalvular leak. There was no second valve implantation. Moreover, no 30-day mortality or complications was reported. Following the transcatheter aortic valve implantation procedure, the heart and valve functions had improved significantly. During the follow-up period of 3-34 months, one patient died of lung cancer 13 months after the operation.

Conclusion

This early experience has provided preliminary evidence for the safety and efficacy of transcatheter aortic valve implantation procedure with the balloon-expandable system in the developing world with an increasing aging population.

Transcatheter aortic valve implantation in the elderly: who to refer?

In recent years, experience with transcatheter aortic valve implantation has led to improved outcomes in elderly patients with severe aortic stenosis (AS) who may not have previously been considered for intervention. These patients are often frail with significant comorbid conditions. As the prevalence of AS increases, there is a need for improved assessment parameters to determine the patients most likely to benefit from this novel procedure. This review discusses the diagnostic criteria for severe AS and the trials available to aid in the decision to refer for aortic valve procedures in the elderly.