Association of Smoking Status With Long-Term Mortality and Health Status After Transcatheter Aortic Valve Replacement: Insights From the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry

Smoker's paradox in transcatheter aortic valve replacement: A National Inpatient Sample analysis from 2015 to 2020

BACKGROUND

While smoking is recognized as a risk factor for multiple cardiovascular conditions, prior research has identified a smoker paradox, wherein smokers had better post-procedural outcomes following transcatheter aortic valve replacement (TAVR) in the initial years of its introduction among high-risk patients only. In recent years, TAVR has expanded to significant larger groups of low-risk patients and became the dominate approach for aortic valve replacement. Consequently, the study cohort from the previous research can no longer represent the current patient populations undergoing TAVR. This study aimed to examine the impact of smoking on TAVR outcomes in the later post-TAVR era.

METHODS

Patients who underwent TAVR were identified in the National Inpatient Sample (NIS) database from the last quarter of 2015-2020 by ICD-10-PCS. Patients were stratified into two cohorts based on smoker status. Multivariable analysis was performed comparing in-hospital post-TAVR outcomes. Adjusted pre-procedural variables included sex, age, race, socioeconomic status, comorbidities, and hospital characteristics.

RESULTS

A total number of 58,934 patients who underwent TAVR were identified including 23,683 smokers and 35,251 non-smokers. Compared to non-smokers, smokers had lower in-hospital mortality (aOR 0.589, p < 0.01), MACE (aOR 0.678, p < 0.01), MI (aOR 0.719, p < 0.01), stroke (aOR 0.599, p < 0.01), neurological complications (aOR 0.653, p < 0.01), pacemaker implantation (aOR 0.911, p < 0.01), cardiogenic shock (aOR 0.762, p < 0.01), respiratory complications (aOR 0.822, p < 0.01), mechanical ventilation (aOR 0.669, p < 0.01), AKI (aOR 0.745, p < 0.01), VTE (aOR 0.578, p < 0.01), hemorrhage/hematoma (aOR 0.921, p < 0.01), infection (aOR 0.625, p < 0.01), vascular complications (aOR 0.802, p < 0.01), reopen surgery (aOR 0.453), and transfer out to another facility (aOR 0.79, p < 0.01). In addition, cigarette smokers had shorter LOS (p < 0.01), and less hospital charge (p < 0.01).

CONCLUSION

This study identified the smoker paradox in the later post-TAVR era with remarkably broad protection from many complications and lower mortality. The reasons underlying this apparent smoker paradox merit deeper investigation.

Occurrence and Persistency of Conduction Disturbances during Transcatheter Aortic Valve Implantation

Background and Objectives: Conduction disturbances such as left bundle branch block (LBBB) and complete atrio-ventricular block (cAVB) are relatively frequent complications following trans-catheter aortic valve implantation (TAVI). We investigated the dynamics of these conduction blocks to further understand luxating factors and predictors for their persistency. Materials and Methods: We prospectively included 157 consecutive patients who underwent a TAVI procedure. Electrocardiograms (ECGs) were obtained at specific time points during the TAVI procedure and at follow-up until at least six months post-procedure. Results: Of the 106 patients with a narrow QRS complex (nQRS) before TAVI, ~70% developed LBBB; 28 (26.4%) being classified as super-transient (ST-LBBB), 20 (18.9%) as transient (T-LBBB) and 24 (22.6%) as persistent (P-LBBB). Risk of LBBB was higher for self-expandable (SE) than for balloon-expandable (BE) prostheses and increased with larger implant depth. During the TAVI procedure conduction disturbances showed a dynamic behavior, as illustrated by alternating kinds of blocks in 18 cases. Most LBBBs developed during balloon aortic valvuloplasty (BAV) and at positioning and deployment of the TAVI prosthesis. The incidence of LBBB was not significantly different between patients who did and did not undergo BAV prior to TAVI implantation (65.3% and 74.2%, respectively (p = 0.494)). Progression to cAVB was most frequent for patients with preexisting conduction abnormalities (5/34) patients) and in patients showing ST-LBBB (6/28). Conclusions: During the TAVI procedure, conduction disturbances showed a dynamic behavior with alternating types of block in 18 cases. After a dynamic period of often alternating types of block, most BBBs are reversible while one third persist. Patients with ST-LBBB are most prone to progressing into cAVB. The observation that the incidence of developing LBBB after TAVI is similar with and without BAV suggests that a subgroup of patients has a substrate to develop LBBB regardless of the procedure.

Smoking and TAVR

See Article Qintar et al.

Association of Smoking Status With Long-Term Mortality and Health Status After Transcatheter Aortic Valve Replacement: Insights From the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry

Background

Smoking is a significant risk factor for aortic stenosis but its impact on clinical and health status outcomes after transcatheter aortic valve replacement (TAVR) has not been described.

Methods and Results

Patients (n=72 165) undergoing TAVR at 457 US sites in the STS/ACC TVT (Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy) Registry between November 2011 and June 2016 were categorized at the time of TAVR as current/recent smokers versus prior/nonsmokers. A series of multivariable models examined the association between smoking status and outcomes, including 1‐year mortality, rehospitalization, mean gradient, and health status (measured by the 12‐item Kansas City Cardiomyopathy Questionnaire–Overall Summary Score [KCCQ‐OS]) and in‐hospital outcomes. A total of 4063 patients (5.6%) were smokers. Smokers presented for TAVR at a younger age (75 [68–81] years versus 83 [77–88] years) but with a greater burden of cardiovascular and lung disease. In adjusted models, smoking was associated with lower in‐hospital mortality (relative risk, 0.74; 95% CI, 0.62–0.89 [P=0.001]) but not with in‐hospital stroke/transient ischemic attack or myocardial infarction. Smoking status had no association with postdischarge mortality, stroke, myocardial infarction, or heart failure (HF) but was associated with slightly lower 1‐year KCCQ‐OS scores (2.4‐point lower KCCQ‐OS; 95% CI, −4.6 to −0.2 [P=0.031]) and higher mean aortic valve gradients (11.1 versus 10.2 mm Hg, P<0.001) in adjusted models.

Conclusions

The current/recent smoking rate in US patients with TAVR is 5.6% and smokers present at a younger age for TAVR. Smoking was associated with lower in‐hospital but similar long‐term survival after TAVR, slightly worse long‐term health status, and marginally higher mean aortic valve gradients. Further research is needed to understand the effect of smoking cessation on outcomes.

See Editorial Edelman and Thourani