The Effect of Coronary Lesion Complexity and Preprocedural Revascularization on 5-Year Outcomes After TAVR

Optimization of Absolute Coronary Blood Flow Measurements to Assess Microvascular Function: In Vivo Validation of Hyperemia and Higher Infusion Speeds

BACKGROUND

Reliable assessment of coronary microvascular function is essential. Techniques to measure absolute coronary blood flow are promising but need validation. The objectives of this study were: first, to validate the potential of saline infusion to generate maximum hyperemia in vivo. Second, to validate absolute coronary blood flow measured with continuous coronary thermodilution at high (40-50 mL/min) infusion speeds and asses its safety.

METHODS

Fourteen closed-chest sheep underwent absolute coronary blood flow measurements with increasing saline infusion speeds at different dosages under general anesthesia. An additional 7 open-chest sheep underwent these measurements with epicardial Doppler flow probes. Coronary flows were compared with reactive hyperemia after 45 s of coronary occlusion.

RESULTS

Twenty milliliters per minute of saline infusion induced a significantly lower hyperemic coronary flow (140 versus 191 mL/min; P=0.0165), lower coronary flow reserve (1.82 versus 3.21; P≤0.0001), and higher coronary resistance (655 versus 422 woods units; P=0.0053) than coronary occlusion. On the other hand, 30 mL/min of saline infusion resulted in hyperemic coronary flow (196 versus 192 mL/min; P=0.8292), coronary flow reserve (2.77 versus 3.21; P=0.1107), and coronary resistance (415 versus 422 woods units; P=0.9181) that were not different from coronary occlusion. Hyperemic coronary flow was 40.7% with 5 mL/min, 40.8% with 10 mL/min, 73.1% with 20 mL/min, 102.3% with 30 mL/min, 99.0% with 40 mL/min, and 98.0% with 50 mL/min of saline infusion when compared with postocclusive hyperemic flow. There was a significant bias toward flow overestimation (Bland-Altman: bias±SD, -73.09±30.52; 95% limits of agreement, -132.9 to -13.27) with 40 to 50 mL/min of saline. Occasionally, ischemic changes resulted in ventricular fibrillation (9.5% with 50 mL/min) at higher infusion rates.

CONCLUSIONS

Continuous saline infusion of 30 mL/min but not 20 mL/min induced maximal hyperemia. Absolute coronary blood flow measured with saline infusion speeds of 40 to 50 mL/min was not accurate and not safe.

Coronary artery disease and its management in TAVI

OBJECTIVE

Aortic stenosis and coronary artery disease (CAD) are frequently associated. The preprocedural evaluation and indications for treatment in patients undergoing transcatheter aortic valve intervention (TAVI) remain controversial. This study sought to 1) determine the prevalence and angiographic characteristics of CAD in TAVI candidates, along with revascularization patterns, and 2) to evaluate the impact of the presence and complexity of CAD, as well as angiography-guided percutaneous coronary intervention, on prognosis after TAVI.

METHODS

Single-center retrospective study from a prospectively collected institutional registry that included all patients that underwent TAVI between 2009 and 2018 and pre TAVI coronary angiography (CA) in our institution in the context of pre-procedure work-up. A multivariate analysis was performed to determine the effect of CAD and PCI on 2-year mortality.

RESULTS

A total of 379 patients were included: 55 patients (14.5%) presented with normal coronary arteries, 120 (31.6%) with non-obstructive CAD, and 204 (53.8%) with obstructive CAD (the mean SxS was 8.2). Ultimately, 110 patients (29%) underwent PCI. Two-year survival after TAVI was decreased in patients with complex coronary lesions (SS > 22), while it was not affected by the overall presence of non-obstructive CAD, obstructive CAD, residual SxS, or pre-TAVI PCI of angiographically significant lesions (OR 0.631, 95%CI 0.192-1.406).

CONCLUSION

In our population, the overall presence and management of obstructive CAD did not appear to impact mortality at 2 years after TAVI. Survival was decreased in patients with baseline complex coronary anatomies.

Differential Effect of Aortic Valve Replacement for Severe Aortic Stenosis on Hyperemic and Resting Epicardial Coronary Pressure Indices

BACKGROUND

Coronary pressure indices to assess coronary artery disease are currently underused in patients with aortic stenosis due to many potential physiological effects that might hinder their interpretation. Studies with varying sample sizes have provided us with conflicting results on the effect of transcatheter aortic valve replacement (TAVR) on these indices. The aim of this meta-analysis was to study immediate and long-term effects of TAVR on fractional flow reserve (FFR) and nonhyperemic pressure ratios (NHPRs).

METHODS AND RESULTS

Lesion-specific coronary pressure data were extracted from 6 studies, resulting in 147 lesions for immediate change in FFR analysis and 105 for NHPR analysis. To investigate the long-term changes, 93 lesions for FFR analysis and 68 for NHPR analysis were found. Lesion data were pooled and compared with paired t tests. Immediately after TAVR, FFR decreased significantly (-0.0130±0.0406 SD, P: 0.0002) while NHPR remained stable (0.0003±0.0675, P: 0.9675). Long-term after TAVR, FFR decreased significantly (-0.0230±0.0747, P: 0.0038) while NHPR increased nonsignificantly (0.0166±0.0699, P: 0.0543). When only borderline NHPR lesions were considered, this increase became significant (0.0249±0.0441, P: 0.0015). Sensitivity analysis confirmed our results in borderline lesions.

CONCLUSIONS

TAVR resulted in small significant, but opposite, changes in FFR and NHPR. Using the standard cut-offs in patients with severe aortic stenosis, FFR might underestimate the physiological significance of a coronary lesion while NHPRs might overestimate its significance. The described changes only play a clinically relevant role in borderline lesions. Therefore, even in patients with aortic stenosis, an overtly positive or negative physiological assessment can be trusted.

Clinical impact of complex percutaneous coronary intervention in the pre-TAVR workup

INTRODUCTION AND OBJECTIVES

In patients undergoing percutaneous coronary intervention (PCI) in the workup pre-transcatheter aortic valve replacement (TAVR), the clinical impact of coronary revascularization complexity remains unknown. This study sought to examine the impact of PCI complexity on clinical outcomes after TAVR in patients undergoing PCI in the preprocedural workup.

METHODS

This was a multicenter study including consecutive patients scheduled for TAVR with concomitant significant coronary artery disease. Complex PCI was defined as having at least 1 of the following features: 3 vessels treated, ≥ 3 stents implanted, ≥ 3 lesions treated, bifurcation with 2 stents implanted, total stent length >60mm, or chronic total occlusion. The rates of major adverse cardiac events (MACE), including cardiovascular mortality, myocardial infarction, and coronary revascularization were evaluated.

RESULTS

A total of 1550 patients were included, of which 454 (29.3%) underwent complex PCI in the pre-TAVR workup. After a median follow-up period of 2 [1-3] years after TAVR, the incidence of MACE was 9.6 events per 100 patients-years. Complex PCI significantly increased the risk of cardiac death (HR, 1.44; 95%CI, 1.01-2.07), nonperiprocedural myocardial infarction (HR, 1.52; 95%CI, 1.04-2.21), and coronary revascularization (HR, 2.46; 95%CI, 1.44-4.20). In addition, PCI complexity was identified as an independent predictor of MACE after TAVR (HR, 1.31; 95%CI, 1.01-1.71; P=.042).

CONCLUSIONS

In TAVR candidates with significant coronary artery disease requiring percutaneous treatment, complex revascularization was associated with a higher risk of MACE. The degree of procedural complexity should be considered a strong determinant of prognosis in the PCI-TAVR population.

Impact of prior coronary artery bypass grafting and coronary lesion complexity on outcomes of transcatheter aortic valve replacement for severe aortic stenosis

OBJECTIVE

To investigate the impact of prior coronary artery bypass grafting (CABG) and coronary lesion complexity on transcatheter aortic valve replacement (TAVR) outcomes for aortic stenosis.

METHODS

Clinical outcomes of TAVR were retrospectively compared between patients with and without prior CABG, and between patients with prior CABG and without coronary artery disease (CAD). The impact of the CABG SYNTAX score was also evaluated in patients with prior CABG.

RESULTS

The study included 1042 patients with a median age and follow-up of 82 years and 25 (range: 0-72) months, respectively. Of these, 175 patients had a history of CABG, while 401 were free of CAD. Patients with prior CABG were more likely to be male and had higher rates of diabetes, peripheral artery disease and atrial fibrillation compared with patients without prior CABG. After 2 : 1 propensity score matching, all-cause mortality (P = 0.17) and the composite of all-cause mortality, stroke and coronary intervention (P = 0.16) were similar between patients with (n = 166) and without (n = 304) prior CABG. A 1 : 1 propensity score-matched analysis, however, showed lower rates of all-cause mortality (P = 0.04) and the composite outcome (P = 0.04) in patients with prior CABG (n = 134) compared with patients without CAD (n = 134). The median CABG SYNTAX score was 16 (interquartile range: 9.0-23), which was not associated with better/worse clinical outcomes in patients with prior CABG.

CONCLUSION

Prior CABG may positively affect mid-term TAVR outcomes for aortic stenosis compared with no CAD when adjusted for other comorbidities. The CABG SYNTAX score did not influence the prognosis after TAVR.

Coronary artery disease and outcomes following transcatheter aortic valve implantation

BACKGROUND

Aortic stenosis is a life-limiting condition for which transcatheter aortic valve implantation (TAVI) is an established therapy. Coronary artery disease (CAD) is frequently found in this patient group and optimal management in these patients remains uncertain.

OBJECTIVES

We sought to examine the association of coexistent CAD on mortality and hospital readmission in patients undergoing TAVI.

METHODS

In this observational cohort study, we examined patients who underwent TAVI and segregated them by the presence of obstructive epicardial CAD. The primary outcome was 3-year mortality with secondary outcomes being readmission for (1) all-causes, (2) a MACE (Major Adverse Cardiovascular Event) composite endpoint and (3) acute coronary syndrome. Subsidiary outcomes included patient angina and breathlessness scores.

RESULTS

898 patients underwent TAVI, of which 488 (54.3%) had unobstructed coronary arteries and 410 (45.7%) had obstructive CAD. Overall, n=298 (33.2%) patients experienced the primary mortality endpoint with no significant difference when stratified according to CAD (n=160 (32.9%) vs n=136 (33.2%), HR 0.98, CI 0.78 to 1.24). After multivariate analysis, the presence of CAD had no effect on the primary outcome (HR 0.98, CI 0.68 to 1.40). There was no significant difference in readmission for any cause (n=181, 37.1% (CAD) vs n=169, 41.2% (no CAD), p=0.23), including no significant difference on readmission for MACE (n=48, 9.8% (CAD) vs n=45, 11.0% (no CAD), p=0.11). CAD at the time of TAVI also did not alter breathlessness or angina scores before/after TAVI (p>0.05).

CONCLUSION

Coexistent CAD had no significant association with mortality, any-cause readmission or symptoms for patients undergoing TAVI in our cohort.

Acute Coronary Syndrome Following Transcatheter Aortic Valve Replacement

Extending the indication of transcatheter aortic valve replacement (TAVR) to younger and lower-risk patients naturally results in longer life expectancy and survival rates after the intervention. The longer life expectancy of these patients leads to an increased possibility of future acute coronary events, necessitating the development of effective and appropriate treatment strategies. Acute coronary syndromes (ACS) in patients with previous TAVR procedures present with modified clinical characteristics when compared to the non-TAVR population. In populations with prior TAVR procedures, plaque rupture remains the main cause of ACS. However, unlike the non-TAVR population, there is an increased frequency of nonatherotrombotic mechanisms, like emboli and mechanical obstruction of coronary ostia by valve components. The main observation related to the treatment of ACS TAVR patients is the significantly lower percentage of patients undergoing invasive management. Furthermore, ACS in TAVR patients is associated with poor prognosis, higher long-term mortality rates, and higher incidence of MACE. It is surprising that considering this significant and increasingly recognized issue, there are only a few studies that have investigated ACS after TAVR. The scope of the present review is to address available data about ACS following TAVR, focusing on incidence, timing, mechanism, and causes. We also examined current knowledge regarding optimal invasive treatment and analyzed short and long-term clinical outcomes.

Insight Into the Optimal Timing of Percutaneous Coronary Intervention and Transcatheter Aortic Valve Replacement

Patients being considered for transcatheter aortic valve replacement (TAVR) are frequently diagnosed with coronary artery disease. In patients requiring revascularization, there is a paucity of data informing when to perform percutaneous coronary artery intervention (PCI). We evaluated the impact of PCI timing on clinical outcomes and readmissions after TAVR. From the National Readmissions Database 2016 to 2019, we stratified the duration between PCI and TAVR into 3 groups: same-day PCI and TAVR, TAVR ≤30 days after PCI, and TAVR >30 days after PCI. We then compared primary and secondary outcomes among them. A total of 5207 patients were included, 1413 (27.1%) of whom underwent PCI and TAVR on the same day, while 2161 (41.5%) underwent TAVR ≤30 days after PCI, and 1632 (31.3%) underwent TAVR >30 days after PCI. There was no significant difference for in-hospital mortality among the groups (adjusted odds ratio [aOR] 0.49, 95% confidence interval [CI] 0.16-1.48, p = 0.203 for same-day versus ≤30 days; aOR 2.07, 95% CI 0.68-6.30, p = 0.199 for same-day versus >30 days). Patients who underwent TAVR ≤30 days after PCI had higher odds of acute kidney injury (aOR 1.49, 95% CI 1.05-2.10, p = 0.024), nonhome discharge (aOR 1.53, 95% CI 1.20-1.96, p = 0.001), and 90-day readmission (aOR 1.35, 95% CI 1.04-1.76, p = 0.026) compared with those who underwent same-day PCI and TAVR. Concomitant PCI and TAVR was associated with lower rates of 90-day readmissions and acute kidney injury compared with TAVR shortly after PCI (<30 days) and should be considered in select patients.

Low levels of circulating methylated IRX3 are related to worse outcome after transcatheter aortic valve implantation in patients with severe aortic stenosis

BACKGROUND

Aortic stenosis (AS) is one of the most common cardiac diseases and major cause of morbidity and mortality in the elderly. Transcatheter aortic valve implantation (TAVI) is performed in such patients with symptomatic severe AS and reduces mortality for the majority of these patients. However, a significant percentage dies within the first two years after TAVI, such that there is an interest to identify parameters, which predict outcome and could guide pre-TAVI patient selection. High levels of cardiac fibrosis have been identified as such independent predictor of cardiovascular mortality after TAVI. Promoter hypermethylation commonly leads to gene downregulation, and the Iroquois homeobox 3 (IRX3) gene was identified in a genome-wide transcriptome and methylome to be hypermethylated and downregulated in AS patients. In a well-described cohort of 100 TAVI patients in which cardiac fibrosis levels were quantified histologically in cardiac biopsies, and which had a follow-up of up to two years, we investigated if circulating methylated DNA of IRX3 in the peripheral blood is associated with cardiac fibrosis and/or mortality in AS patients undergoing TAVI and thus could serve as a biomarker to add information on outcome after TAVI.

RESULTS

Patients with high levels of methylation in circulating IRX3 show a significantly increased survival as compared to patients with low levels of IRX3 methylation indicating that high peripheral IRX3 methylation is associated with an improved outcome. In the multivariable setting, peripheral IRX3 methylation acts as an independent predictor of all-cause mortality. While there is no significant correlation of levels of IRX3 methylation with cardiac death, there is a significant but very weak inverse correlation between circulating IRX3 promoter methylation level and the amount of cardiac fibrosis. Higher levels of peripheral IRX3 methylation further correlated with decreased cardiac IRX3 expression and vice versa.

CONCLUSIONS

High levels of IRX3 methylation in the blood of AS patients at the time of TAVI are associated with better overall survival after TAVI and at least partially reflect myocardial IRX3 expression. Circulating methylated IRX3 might aid as a potential biomarker to help guide both pre-TAVI patient selection and post-TAVI monitoring.

Trends and Outcomes in Patients With Coronary Artery Disease Undergoing TAVR: Insights From VA CART

Background

Obstructive coronary artery disease (CAD) is common in patients with severe symptomatic aortic stenosis. The management and impact of obstructive CAD in patients undergoing transcatheter aortic valve replacement (TAVR) have not been fully evaluated. We aimed to determine the patient characteristics and clinical outcomes among veterans undergoing TAVR with and without obstructive CAD and to determine temporal trends and association of pre-TAVR percutaneous coronary intervention (PCI) with clinical outcomes.

Methods

We identified all patients who underwent TAVR from 2012 to 2021 in the VA Health Care System. The sample population was divided into patients with and without obstructive CAD and further stratified by coronary intervention status 1 year prior to TAVR. The primary outcome was 1-year all-cause mortality, and the secondary outcome was major bleeding.

Results

During the study period, 759 patients underwent TAVR, and 282 (37%) had obstructive CAD. Obstructive CAD was associated with higher 1-year mortality (15.6% vs 7.1%; P < .01) after TAVR. The rate of PCI prior to TAVR increased from 2012 until 2016, after which it steadily declined such that 144 patients (51%) underwent PCI pre-TAVR during the entire study period. There was no difference in 1-year mortality (16.0% vs 15.2%; P = .89) or bleeding (16.7% vs 12.3%; P = .33) between patients who underwent or did not undergo pre-TAVR PCI.

Conclusions

Among veterans undergoing TAVR, the presence of obstructive CAD is associated with higher mortality though pre-TAVR coronary intervention is not associated with improved outcomes. Further studies could identify a subset of patients who may benefit from coronary revascularization prior to TAVR.

Asymptomatic Severe and Moderate Aortic Stenosis: Time for Appraisal of Treatment Indications

Over the last decades, we have witnessed considerable improvements in diagnostics and risk stratification of patients with significant aortic stenosis (AS), paralleled by advances in operative and anesthetic techniques. In addition, accumulating evidence points to the potential benefit of early valve replacement in such patients prior to the onset of symptoms. In parallel, interventional randomized trials have proven the benefit of transcatheter aortic valve replacement in comparison to a surgical approach to valve replacement over a broad risk spectrum in symptomatic patients with AS. This article reviews contemporary management approaches and scrutinizes open questions regarding timing and mode of intervention in asymptomatic patients with severe AS. We also discuss the challenges surrounding the management of symptomatic patients with moderate AS as well as emerging dilemmas related to the concept of a life-long treatment strategy for patients with AS.

Gender Differences in the Impact of Coronary Artery Disease and Complete Revascularization on Long-Term Outcomes After Transcatheter Aortic Valve Implantation

In this study, we compare gender-specific clinical outcomes. We show that outcomes among women after transcatheter aortic valve implantation are significantly influenced by co-existing coronary artery disease (CAD) and its complexity, whereas in men, this is less pronounced. Moreover, we identified a subgroup of women with complex CAD who are at particularly high risk for fatal cardiovascular events, even when compared with men with similar CAD.