Searching for the Smoker’s Paradox in Acute Stroke Patients Treated With Intravenous Thrombolysis

The objective of this study was to determine the prevalence of intracranial plaques and stenoses and their causal role in patients with fatal stroke. Intracranial atherosclerosis is considered to be a rare condition with a severe prognosis. However, disease prevalence may be underestimated due to lack of appropriate diagnostic procedures. We performed a systematic analysis of intra- and extracranial arteries, the aortic arch, and the heart in 339 consecutive autopsies of patients with stroke. Clinical history, risk factors, imaging data, and general autopsy reports were analyzed. Patients with brain hemorrhage (n=80) were used as control subjects. Intracranial plaques and stenoses occurred in 62.2% (95% CI, 56.3 to 68.1) and 43.2% (95% CI, 37.2 to 49.3) of patients with brain infarction, respectively, compared with 48.8% (P 30%, the stenosis was considered to be causal in 5.8% of cases (n=15) because of superimposed clot on ulcerated plaques; 27% of these patients had stenoses graded 30% to 75%. In multivariate analyses, diabetes and male sex were significantly associated with intracranial plaques and stenosis. History of myocardial infarction was significantly associated with intracranial plaques and previous stroke was associated with intracranial stenosis. Intracranial plaques and stenoses are highly prevalent in fatal stroke, and stenoses graded 30% to 75% may be causal. New arterial wall imaging techniques should be used to reevaluate the frequency and role of intracranial artery plaques in living patients with stroke.

Electron beam tomography (EBT) is a noninvasive method used to detect coronary artery calcium (CAC). Due to the age-associated increase in incidence and magnitude of CAC, interpretation of results can be difficult. The purpose of this study was to develop a set of age- and gender-stratified CAC distributions to serve as standards for the clinical interpretation of EBT scans. Between 1993 and 1999, 35,246 asymptomatic subjects, 30 to 90 years of age, were self-referred for CAC screening using an Imatron EBT scanner. CAC score was calculated based on the number, areas, and peak computed tomographic density for each detected calcific lesion. CAC score in each coronary artery was equal to the sum of all lesions for that artery and the total CAC score was equal to the sum of the score of each artery. Total CAC scores were assigned to a percentile according to age and gender. CAC scores were reported at the 10th, 25th, 50th, 75th, and 90th percentiles for 16 age and/or gender groups. The prevalence of CAC increased with age for men and women. The extent of CAC differed significantly between men and women in the same age group. In summary, this study reports the distribution of CAC score by age and gender. Knowledge of the distribution of CAC, the effect of age on the total CAC score as well as the differences in total CAC scores that exist between men and women of similar age will assist the clinician in interpreting EBT CAC results.

We sought to determine the relationship between cigarette smoking and outcomes after mechanical reperfusion therapy in acute myocardial infarction (AMI). Prior studies have found that smokers with AMI have lower mortality rates and a more favorable response to fibrinolytic therapy than nonsmokers. The impact of cigarette smoking in patients undergoing primary percutaneous coronary intervention has not been examined. In the CADILLAC trial, 2082 patients with AMI were randomized to percutaneous transluminal coronary angioplasty +/- abciximab versus stenting +/- abciximab. Data on smoking status were prospectively collected and follow-up continued for 1 year. At the time of presentation, 638 (31%) patients had never smoked, 546 (26%) were former smokers, and 898 (45%) were currently smoking. In comparison to nonsmokers, current smokers were younger, more often men, and less frequently had diabetes, hypertension, prior AMI, and triple-vessel coronary disease. Procedural success rates were unrelated to smoking status. Mortality was lowest in current smokers, intermediate in former smokers, and highest in nonsmokers at 30 days (1.3% vs 1.7% vs 3.5%, respectively, P = .02) and 1 year (2.9% vs 3.7% vs 6.6%, P = .0008). After multivariate correction for differences in baseline variables, however, current smoking status was no longer protective from late mortality (hazard ratio 0.96, 95% CI 0.52-1.76, P = .89). The "smoker's paradox" extends to patients undergoing primary PCI for AMI, with increased survival seen in current smokers, an effect entirely explained by differences in baseline risk and not smoking status per se. The deleterious effects of smoking are expressed in the occurrence of AMI nearly a decade earlier than in nonsmokers, with similar age-adjusted risk, mandating intensive primary and secondary cigarette-cessation efforts.