Smoke Signals: Unraveling the Paradoxical Impact of Smoking on Stroke Prognosis and Treatment Efficacy

Smoking is a well-established risk factor for stroke, yet its impact on stroke prognosis remains complex and multifaceted. This systematic review aims to elucidate the relationship between smoking and various stroke outcomes, including response to treatment and long-term recovery. We conducted a comprehensive analysis of four fundamental studies that examined the prognosis of stroke in smokers, focusing on clinical outcomes post-endovascular treatment, response to antiplatelet therapy, incidence of post-stroke delirium, and the effectiveness of thrombolysis treatment. The studies varied in design, including observational, retrospective, and post hoc trial analyses. The review reveals that smoking may paradoxically predict better clinical outcomes in specific treatment scenarios, such as post-endovascular treatment and when using clopidogrel. However, smokers also demonstrated higher rates of ischemic stroke and post-stroke delirium. Notably, the smoker's paradox in thrombolysis treatment was not supported. These findings highlight the need for personalized treatment approaches based on smoking status. Smoking has a complex and significant impact on stroke prognosis. While some benefits in specific treatment contexts were observed, the overall evidence strongly advises against smoking due to its adverse health consequences. This review underscores the importance of personalized stroke management in smokers and the integration of smoking cessation programs in post-stroke care. Future research should focus on larger, longitudinal studies to explore these associations further.

Prevalence and impact of tobacco use disorder on in-hospital mortality in patients hospitalized with non-group 1 pulmonary hypertension: a nationwide propensity score-matched analysis, 2019

Numerous studies indicated that patients with tobacco use disorder (TUD) are inversely associated with mortality in what is known as the smoker's paradox. However, limited studies have been conducted on the impact of TUD on the in-hospital mortality rates of patients with secondary pulmonary hypertension (PH, Non-Group 1 PH). Using the 2019 National Inpatient Sample, we identified PH and divided it into TUD and non-TUD to compare the comorbidities and in-hospital mortality between the two after 1:1 propensity-score matching. Of 1,129,440 PH hospitalizations, 12.1 % had TUD. After matching (n=133545, each group), TUD had lower median age (62 vs. 63), higher females (49 vs. 46.6 %), blacks (25.9 vs. 25.3 %), lower household income (40.8 vs. 32.7 %), Medicaid (22.4 vs. 14.8 %), non-elective (93.5 vs. 89.8 %), rural (9.3 vs. 6.7 %), urban non-teaching (17.2 vs 15.8 %) admissions. All CV comorbidities and other substance use were higher in TUD except CHF and valvular heart disease, TUD+ cohort and lower mortality (3.3 vs. 4.2 %, OR 0.78, p<0.001), higher routine discharges (53.8 vs. 51.3 %, p<0.001) and lower total charges ($47155 vs. 51909, p<0.001) than non-TUD. Although PH patients with TUD had a higher comorbidity burden, they had lower in-hospital mortality rates along with lower total charges of hospitalization, mandating real-world data to validate these results. See also the Graphical abstract(Fig. 1).

No Paradoxical Effect of Smoking Status on Recurrent Cardiovascular Events in Patients Following Percutaneous Coronary Intervention: Thai PCI Registry

Background

"Smoker's paradox" is a controversial phenomenon that describes an unexpectedly favorable short-term outcome of smokers post-percutaneous coronary intervention (PCI). This study aimed to evaluate the effect of smoking status on recurrent major adverse cardiovascular events (MACEs) in patients who recently underwent PCI and to determine whether it was paradoxical.

Methods

This study utilized data from the nationwide Thai PCI registry, enrolling patients during 2018-2019. Our study factor was smoking status, classified as current smokers, ex-smokers, and nonsmokers. The outcome of interest was the time to occurrence of a composite of MACEs (i.e., all-cause death, myocardial infarction (MI), stroke, and unplanned revascularization) evaluated at about 1-year post-PCI. A propensity score (PS) model using inverse probability weighting with regression adjustment was used to estimate the effect of smoking on the occurrence of MACE.

Results

Current smokers, ex-smokers, and non-smokers accounted for 23, 32, and 45% of the 22,741 subjects, respectively. Smokers were younger, more frequently male, and had fewer traditional atherosclerotic risk factors. Current smokers presented more frequently with ST-elevation MIs (STEMIs) and cardiogenic shock (54 and 14.6%, respectively) than non-smokers. MACE rates were 1.9, 1.2, and 1.6 per 100 patients per month in the current smokers, ex-smokers, and non-smokers, respectively. After applying a PS, patients with a history of current smoking and ex-smoking developed the onset of recurrent MACEs significantly sooner than non-smokers, with a median time of 4.4 vs. 4.9 vs. 13.5 months (p < 0.001), respectively.

Conclusions

"Smoker's paradox" was not observed in our patient population. Current smokers and ex-smokers were prone to develop an earlier onset of a post-PCI MACEs than nonsmokers and need a smoke cessation program for further prevention.

Correlation Between Smoking Paradox and Heart Rhythm Outcomes in Patients With Coronary Artery Disease Receiving Percutaneous Coronary Intervention

BACKGROUND

The effect of smoking on short-term outcomes among patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) is controversial. However, little is known about the impact of smoking on long-term outcomes in patients with stable coronary artery disease (CAD) who receive PCI.

METHODS

A total of 2,044 patients with stable CAD undergoing PCI were evaluated. They were divided into two groups according to smoking status (current smokers vs. non-smokers). Baseline characteristics, exposed risk factors, angiographic findings, and interventional strategies were assessed to compare the long-term clinical outcomes between groups. Predictors for myocardial infarction (MI), all-cause death, cardiovascular (CV) death, and repeated PCI procedures were also analyzed.

RESULTS

Compared with non-smokers, current smokers were younger and mostly male (both P < 0.01). They also had a lower prevalence of chronic kidney disease (CKD) and diabetes (both P < 0.01). Drugs including a P2Y12 receptor inhibitor of platelets (P2Y12 inhibitor), beta-blockers (BB), and statins were used more frequently in current smokers (P < 0.01, P < 0.01, P = 0.04, respectively). Freedom from all-cause death and CV death was lower in the non-smoker group (P < 0.001, P = 0.003, respectively). After adjustment, logistic regression revealed smoking was a major predictor for all-cause death and repeated PCI procedure [hazard ratio(HR): 1.71 and 1.46, respectively].

CONCLUSIONS

Smoker's paradox extends to long-term outcome in patients with stable CAD undergoing PCI, which is partially explained by differences in baseline characteristics. However, smoking strongly predicted all-cause mortality and repeated PCI procedures in patients with stable CAD undergoing PCI.

Smoker's Paradox in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Prior studies have found that smokers undergoing thrombolytic therapy for ST-segment elevation myocardial infarction have lower in-hospital mortality than nonsmokers, a phenomenon called the "smoker's paradox." Evidence, however, has been conflicting regarding whether this paradoxical association persists in the era of primary percutaneous coronary intervention.

METHODS AND RESULTS

We used the 2003-2012 National Inpatient Sample databases to identify all patients aged ≥18 years who underwent primary percutaneous coronary intervention for ST-segment elevation myocardial infarction. Multivariable logistic regression was used to compare in-hospital mortality between smokers (current and former) and nonsmokers. Of the 985 174 patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention, 438 954 (44.6%) were smokers. Smokers were younger, were more often men, and were less likely to have traditional vascular risk factors than nonsmokers. Smokers had lower observed in-hospital mortality compared with nonsmokers (2.0% versus 5.9%; unadjusted odds ratio 0.32, 95% CI 0.31-0.33, P<0.001). Although the association between smoking and lower in-hospital mortality was partly attenuated after baseline risk adjustment, a significant residual association remained (adjusted odds ratio 0.60, 95% CI 0.58-0.62, P<0.001). This association largely persisted in age-stratified analyses. Smoking status was also associated with shorter average length of stay (3.5 versus 4.5 days, P<0.001) and lower incidence of postprocedure hemorrhage (4.2% versus 6.1%; adjusted odds ratio 0.81, 95% CI 0.80-0.83, P<0.001) and in-hospital cardiac arrest (1.3% versus 2.1%; adjusted OR 0.78, 95% CI 0.76-0.81, P<0.001).

CONCLUSIONS

In this nationwide cohort of patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction, we observed significantly lower risk-adjusted in-hospital mortality in smokers, suggesting that the smoker's paradox also applies to ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention.

Impact of cigarette smoking on extent of coronary artery disease and prognosis of patients with non-ST-segment elevation acute coronary syndromes: an analysis from the ACUITY Trial (Acute Catheterization and Urgent Intervention Triage Strategy)

OBJECTIVES

This study sought to evaluate the short- and long-term outcomes for smokers with non-ST-segment elevation acute coronary syndromes (NSTE-ACS).

BACKGROUND

Smoking has been associated with the "paradox" of reduced mortality after acute myocardial infarction (MI). This is thought to be due to favorable baseline characteristics and less diffuse coronary artery disease (CAD) among smokers.

METHODS

In the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial, 13,819 patients (29.1% smokers) with moderate- to high-risk NSTE-ACS underwent angiography and, if indicated, revascularization.

RESULTS

Smokers were significantly younger and had fewer comorbidities than nonsmokers. Incidence of death and MI were comparable at 30 days, although smokers had significantly reduced risks of 30-day major bleeding (hazard ratio [HR]: 0.80, 95% confidence interval [CI]: 0.67 to 0.96; p = 0.016) and 1-year mortality (HR: 0.797, 95% CI: 0.65 to 0.97; p = 0.027). After correction for baseline and clinical differences, smoking was no longer predictive of major bleeding (odds ratio: 1.06, 95% CI: 0.86 to 1.32; p = 0.56) and was associated with higher 1-year mortality (HR: 1.37, 95% CI: 1.07 to 1.7; p = 0.013). This pattern of reversed risk after multivariable correction held true for those smokers requiring percutaneous coronary intervention. Core laboratory angiographic analysis showed that smokers and nonsmokers were comparable in terms of the extent of CAD, Thrombolysis In Myocardial Infarction flow, myocardial blush, and the presence of thrombi.

CONCLUSIONS

In contrast to the paradox previously described in ST-segment elevation MI, our analysis finds smoking to be an independent predictor of higher 1-year mortality in patients presenting with NSTE-ACS, and our angiographic study demonstrates CAD in smokers that is comparable to that in nonsmokers but evident ∼1 decade earlier. (Acute Catheterization and Urgent Intervention Triage Strategy [ACUITY]; NCT00093158).