The SURTAVI study: TAVI for patients with intermediate risk

Predictors and neurological consequences of periprocedural cerebrovascular events following transcatheter aortic valve implantation with self-expanding valves

Aims

To evaluate the patient- and procedure-related predictors of transcatheter aortic-valve implantation (TAVI)-associated ischemic brain lesions and to assess the effect of silent cerebral ischemic lesions (SCIL) on neurocognitive function.

Methods and results

We investigated 113 consecutive patients with severe aortic stenosis who underwent brain magnetic resonance imaging (MRI) within a week following TAVI. To assess periprocedural cerebral ischemic lesions, diffusion-weighted MRI was utilized. We used multivariate linear regression to identify the independent predictors of TAVI-related ischemic lesion volume (ILV) and periprocedural stroke. Neurocognitive evaluation was performed before and following TAVI at 6-month and one-year follow-up. Following TAVI, a total of 944 new cerebral ischemic lesions were detected in 104 patients (92%). The median ILV was 257 μl (interquartile range [IQR]:97.1–718.8μl) with a median lesion number of 6/patient [IQR:2–10]. The majority of ischemic lesions were clinically silent (95%), while 5% of the lesions induced a stroke, which was confirmed by MRI. Predilatation (β = 1.13[95%CI:0.32–1.93], p = 0.01) and the number of valve positioning attempts during implantation (β = 0.28[95%CI:0.06–0.50], p = 0.02) increased the log-transformed total ILV. Predilatation (OR = 12.04[95%CI:1.46–99.07], p = 0.02) and alternative access routes (OR = 7.84[95%CI:1.01–61.07], p = 0.02) were associated with stroke after adjustments for comorbidities and periprocedural factors. The presence of SCILs were not associated with a change in neurocognitive function that remained stable during the one-year follow-up.

Conclusion

While periprocedural ischemic lesions are frequent, most of them are clinically silent and might not impact the patients' neurocognitive function. The number of valve positioning attempts, predilatation, and alternative access routes should be taken into consideration during TAVI to reduce the ILV and risk for stroke.

Comparing Trajectory of Surgical Aortic Valve Replacement in the Early vs. Late Transcatheter Aortic Valve Replacement Era

Background: Traditionally, the only effective treatment for aortic stenosis was surgical aortic valve replacement (SAVR). Transcatheter aortic valve replacement (TAVR) was approved in the United States in late 2011 and provided a critical alternative therapy. Our aims were to investigate the trends in the utilization of SAVR in the early vs. late TAVR era and to assess SAVR and TAVR outcomes. Methods: Using the 2011-2017 National Inpatient Sample database, we identified hospitalizations for patients with a most responsible diagnosis of aortic stenosis during which an aortic valve replacement (AVR) was performed, either SAVR or TAVR. Patients' sociodemographic and clinical characteristics, procedure complications, length of stay, and mortality were analyzed. Multivariable analyses were performed to identify predictors of in-hospital mortality. Piecewise regression analyses were performed to assess temporal trends in SAVR and TAVR utilization. Results: A total of 542,734 AVR procedures were analyzed. The utilization of SAVR was steady until 2014 with a significant downward trend in the following years 2015-2017 (P = 0.026). In contrast, a steady upward trend was observed in the TAVR procedure with a significant increase during the years 2015-2017 (P = 0.006). Higher in-hospital mortality was observed in SAVR patients. The mortality rate declined from 2011 to 2017 in a significantly higher proportion in the TAVR compared with the SAVR group. Conclusion: Utilization of SAVR showed a downward trend during the late TAVR era (2015-2017), and TAVR utilization demonstrated a steady upward trend during the years 2011-2017. Higher in-hospital mortality was recorded in patients who underwent SAVR.

The effect of Remote Ischemic Preconditioning (RIPC) on myocardial injury and inflammation in patients with severe aortic valve stenosis undergoing Transcatheter Aortic Valve Replacement (TAVΙ)

BACKGROUND

Remote ischemic preconditioning (RIPC) is being evaluated as a strategy to reduce cardiac injury and inflammation in patients undergoing diverse cardiac invasive and surgical procedures. However, it is unclear whether RIPC has protective effects in patients undergoing the transfemoral- transcatheter aortic valve implantation (TF-TAVΙ) procedure.

METHODS

Between September 2013 and September 2015, 55 random consecutive patients were prospectively assigned to receive SHAM preconditioning (SHAM, 22 patients) or Remote Ischemic Preconditioning (RIPC) (4 cycles of 5 min intermittent leg ischemia and 5 min reperfusion, 33 patients) prior to TF-TAVI. The primary endpoint was to determine the serum levels of: hs-cTn-I (necrosis), CK-18 (apoptosis), and IL-1b (inflammation). Quantification was performed using commercially available ELISA kits. Patients were sampled 1-day pre TF-TAVΙ and 24-hours post TF-TAVΙ. Secondary endpoints included: total mortality, incidence of periprocedural clinical acute myocardial infarction (AMI), acute kidney injury (AKI), and stroke.

RESULTS

22 SHAM patients and 33 RIPC patients were finally analyzed. Our data revealed no significant difference in serum levels of hs-cTn-I and CK-18 among various groups. However, in the RIPC group, the increase in IL1b level was significantly lower for 24-h post TF-TAVΙ, (p < 0.01). There were no significant differences between groups in the secondary endpoints at the follow-up interval of one month. RIPC-related adverse events were not observed.

CONCLUSIONS

Our data suggest that RIPC did not exhibit significant cardiac or kidney protective effects regarding necrosis and apoptosis in patients undergoing TF-TAVΙ. However, an important anti-inflammatory effect was detected in the RIPC group.

Pre- and Post-Transcatheter Aortic Valve Replacement Serum Brain Natriuretic Peptide Levels and All-Cause Mortality

BACKGROUND

Risk stratification in patients post-transcatheter aortic valve replacement (TAVR) is limited to and is based on clinical judgment and surgical scoring systems. Serum natriuretic peptides are used for general risk stratification in patients with aortic stenosis, reflecting the increase in their afterload and thereby stressing the need for valve intervention. The objective of this study was to determine the predictive value of pre- and post-procedural serum brain natriuretic peptide (BNP) on 1-year all-cause mortality in patients who underwent TAVR.

METHODS

In this population-based study, we included 148 TAVR patients treated at the Poriya Medical Center between June 1, 2015, and May 31, 2018. Routine blood samples for serum BNP levels (pg/mL) were taken just before the TAVR and 24 h post-TAVR. Our primary clinical outcome was defined as 1-year all-cause mortality. We used backward regression models and included all variables that had a p value <0.1 in the univariable analysis. A receiver-operating characteristic curve was calculated for the prediction of all-cause mortality by serum BNP levels using the median as the cut-off point.

RESULTS

In this study cohort, BNP levels 24 h post-TAVR higher than the cohort median versus lower than the cohort median (387.5 pg/mL; IQR 195-817.6) were the strongest predictor of 1-year mortality (hazard ratio 9; 95% CI 2.72-30.16; p < 0.001). The statistically significant relationship was seen in the unadjusted regression model as well as after the adjustment for clinical variables.

CONCLUSIONS

Serum BNP levels 24 h post-procedure were found to be a meaningful marker in predicting 1-year all-cause mortality in patients after TAVR procedure.

Recent advances in aortic valve replacement

Aortic valve replacement has stood the test of time but is no longer an operation that is exclusively approached through a median sternotomy using only sutured prostheses. Currently, surgical aortic valve replacement can be performed through a number of minimally invasive approaches employing conventional mechanical or bioprostheses as well as sutureless valves. In either case, the direct surgical access allows inspection of the valve, complete excision of the diseased leaflets, and debridement of the annulus in a controlled and thorough manner under visual control. It can be employed to treat aortic valve pathologies of all natures and aetiologies. When compared with transcatheter valves in patients with a high or intermediate preoperative predictive risk, conventional surgery has not been shown to be inferior to transcatheter valve implants. As our understanding of sutureless valves and their applicability to minimally invasive surgery advances, the invasiveness and trauma of surgery can be reduced and outcomes can improve. This warrants further comparative trials comparing sutureless and transcatheter valves.

Profiling Hospital Performance on the Basis of Readmission After Transcatheter Aortic Valve Replacement in Ontario, Canada

Background

Readmission rates are a widely accepted quality indicator. Our objective was to develop models for calculating case‐mixed adjusted readmission rates after transcatheter aortic valve replacement for the purpose of profiling hospitals.

Methods and Results

In this population‐based study in Ontario, Canada, we identified all transcatheter aortic valve replacement procedures between April 1, 2012, and March 31, 2016. For each hospital, we first calculated 30‐day and 1‐year risk‐standardized (predicted versus expected) readmission rates, using 2‐level hierarchical logistic regression models, including clustering of patients within hospitals. We also calculated the risk‐adjusted (observed versus expected) readmission rates, accounting for the competing risk of death using a Fine‐Gray competing risk model. We categorized hospitals into 3 groups: those performing worse than expected, those performing better than expected, or those performing as expected, on the basis of whether the 95% CI was above, below, or included the provincial average readmission rate respectively. Our cohort consisted of 2129 transcatheter aortic valve replacement procedures performed at 10 hospitals. The observed readmission rate was 15.4% at 30 days and 44.2% at 1 year, with a range of 10.9% to 21.7% and 38.8% to 55.0%, respectively, across hospitals. Incorporating the competing risk of death translated into meaningful different results between models; as such, we concluded that the risk‐adjusted readmission rate was the preferred metric. On the basis of the 30‐day risk‐adjusted readmission rate, all hospitals performed as expected, with a 95% CI that included the provincial average. However, we found that there was significant variation in 1‐year risk‐adjusted readmission rate.

Conclusions

There is significant interhospital variation in 1‐year adjusted readmission rates among hospitals, suggesting that this should be a focus for quality improvement efforts in transcatheter aortic valve replacement.

Profiling Hospital Performance Based on Mortality After Transcatheter Aortic Valve Replacement in Ontario, Canada

BACKGROUND

Public reporting of hospital-level outcomes is increasingly common as a means to target quality improvement strategies to ensure the delivery of optimal care. Despite the rapid dissemination of transcatheter aortic valve replacement (TAVR), there is a paucity of reliable case-mix adjustment models for hospital profiling in TAVR. Our objective was to develop and evaluate different models for calculating risk-standardized all-cause mortality rates (RSMRs) post-TAVR.

METHODS AND RESULTS

In this population-based study in Ontario, Canada, we identified all patients who underwent a TAVR procedure between April 1, 2012, and March 31, 2016. For each hospital, we calculated 30-day and 1-year RSMR, using 2-level hierarchical logistic regression models that accounted for patient-specific demographic and clinical characteristics, as well as the clustering of patients within the same hospital using a hospital-specific random effects. We classified each hospital into one of 3 groups: performing worse than expected, better than expected, or performing as expected, based on whether the 95% CI of the RSMR was above, below, or included the provincial average mortality rate, respectively. Our cohort consisted of 2129 TAVR procedures performed at 10 hospitals. The observed mortality was 7.0% at 30 days and 16.4% at 1 year, with a range of 4% to 10% and 8% to 22%, respectively, across hospitals. We developed case-mix adjustment models using 28 clinically relevant variables. Using 30-day and 1-year RSMR to profile each hospital, we found that all hospitals performed as expected, with 95% CI that included the provincial average.

CONCLUSIONS

We found no significant interhospital variation in RSMR among hospitals, suggesting that quality improvement efforts should be directed at aspects other than the variation in observed mortality.

Temporal Trends and Clinical Consequences of Wait Times for Transcatheter Aortic Valve Replacement

Background:

Transcatheter aortic valve replacement (TAVR) represents a paradigm shift in the therapeutic options for patients with severe aortic stenosis. However, rapid and exponential growth in TAVR demand may overwhelm capacity, translating to inadequate access and prolonged wait times. Our objective was to evaluate temporal trends in TAVR wait times and the associated clinical consequences.

Methods:

In this population-based study in Ontario, Canada, we identified all TAVR referrals from April 1, 2010, to March 31, 2016. The primary outcome was the median total wait time from referral to procedure. Piecewise regression analyses were performed to assess temporal trends in TAVR wait times, before and after provincial reimbursement in September 2012. Clinical outcomes included all-cause death and heart failure hospitalizations while on the wait list.

Results:

The study cohort included 4461 referrals, of which 50% led to a TAVR, 39% were off-listed for other reasons, and 11% remained on the wait list at the conclusion of the study. For patients who underwent a TAVR, the estimated median wait time in the postreimbursement period stabilized at 80 days and has remained unchanged. The cumulative probability of wait-list mortality and heart failure hospitalization at 80 days was ≈2% and 12%, respectively, with a relatively constant increase in events with increased wait times.

Conclusions:

Postreimbursement wait time has remained unchanged for patients undergoing a TAVR procedure, suggesting the increase in capacity has kept pace with the increase in demand. The current wait time of almost 3 months is associated with important morbidity and mortality, suggesting a need for greater capacity and access.

Technique and Patient Selection Criteria of Right Anterior Mini-Thoracotomy for Minimal Access Aortic Valve Replacement

Aortic valve stenosis has become the most prevalent valvular heart disease in developed countries, and is due to the aging of these populations. The incidence of the pathology increases with growing age after 65 years. Conventional surgical aortic valve replacement through median sternotomy has been the gold standard of patient care for symptomatic aortic valve stenosis. However, as the risk profile of patients worsens, other therapeutic strategies have been introduced in an attempt to maintain the excellent results obtained by the established surgical treatment. One of these approaches is represented by transcatheter aortic valve implantation. Although the outcomes of high-risk patients undergoing treatment for symptomatic aortic valve stenosis have improved with transcatheter aortic valve replacement, many patients with this condition remain candidates for surgical aortic valve replacement. In order to reduce the surgical trauma in patients who are candidates for surgical aortic valve replacement, minimally invasive approaches have garnered interest during the past decade. Since the introduction of right anterior thoracotomy for aortic valve replacement in 1993, right anterior mini-thoracotomy and upper hemi-sternotomy have become the predominant incisional approaches among cardiac surgeons performing minimal access aortic valve replacement. Beside the location of the incision, the arterial cannulation site represents the second major landmark of minimal access techniques for aortic valve replacement. The two most frequently used arterial cannulation sites include central aortic and peripheral femoral approaches. With the purpose of reducing surgical trauma in these patients, we have opted for a right anterior mini-thoracotomy approach with a central aortic cannulation site. This protocol describes in detail a technique for minimally invasive aortic valve replacement and provides recommendations for patient selection criteria, including cardiac computer tomography measurements. The indications and limitations of this technique, as well as its alternatives, are discussed.