[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to evaluate the impact of smoking in patients with left ventricular dysfunction.
The impact of smoking in patients with left ventricular dysfunction has not been well-studied.
We compared the incidence of death, hospitalization due to heart failure and myocardial infarction (MI) in current smokers to ex-smokers of < or =2 years and ex-smokers of >2 years duration to never-smokers among participants of the Study Of Left Ventricular Dysfunction (SOLVD) Prevention and Intervention trials. Participants all had left ventricular ejection fraction (LVEF) <35% and follow-up was over a mean of 41 months.
Complete smoking status and outcome data were available in 6,704 subjects. There were 1,562 current smokers, 1,317 ex-smokers of < or =2 years, 2,354 ex-smokers of >2 years and 1,471 never-smokers. After adjusting for baseline differences of age, LVEF, race and etiology of heart failure, current smoking was associated with a significantly increased all-cause mortality (relative risk [RR]: 1.41, 95% confidence interval [CI]: 1.25 to 1.58, p < 0.001) compared with ex-smokers and never-smokers. The incidence of death or recurrent congestive heart failure requiring hospitalization or MI was significantly greater (RR: 1.39, 95% CI: 1.26 to 1.52, p < 0.001) in current smokers compared with ex-smokers and never-smokers. There were no significant differences in the number of deaths or hospitalizations due to heart failure between ex-smokers and never-smokers. This effect was consistent across both the SOLVD Prevention and Treatment trials.
Current smoking is a powerful independent predictor of morbidity (recurrent heart failure and MI) and mortality in patients with left ventricular dysfunction. Quitting smoking appears to have a substantial and early effect (within two years) on decreasing morbidity and mortality in patients with left ventricular dysfunction, which is at least as large as proven drug treatments recommended in patients with left ventricular dysfunction.
Journal of the American College of Cardiology 05/2001; 37(6):1677-82. · 15.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cardiovascular disease and cancer are important health problems worldwide, yet our knowledge of these conditions is derived principally from populations of European descent. To investigate ethnic variations in major causes of death in Canada, the authors examined total and cause-specific mortality among European, south Asian, and Chinese Canadians.
Canadians of European, south Asian and Chinese origin were identified in the Canadian Mortality Database by last name and country of birth and in the population census by self-reported ethnicity. Age-standardized death rates by cause, per 100,000 population, were calculated for ages 35 to 74 years from 1979 to 1993 and in 5-year intervals grouped around census years (1979/83, 1984/88 and 1989/93).
Rates of death from ischemic heart disease were highest among Canadians of south Asian origin (men 320.2, women 144.5) and European origin (men 319.6, women 109.9) and were markedly lower among Canadians of Chinese origin (men 107.0, women 40.0); the rates declined significantly in all 3 groups over the study period. Rates of death from cerebrovascular disease were relatively low and showed less ethnic variation (Canadian men of European, south Asian and Chinese origin 49.5, 47.0 and 45.8 respectively; Canadian women of European, south Asian and Chinese origin 34.8, 39.0 and 42.2 respectively) and declined similarly in all groups over time. Rates of death from cancer were highest among Canadians of European origin (men 343.6, women 236.2), intermediate among those of Chinese origin (men 258.1, women 161.6) and lowest among those of south Asian origin (men 122.3, women 131.3). Over time, cancer mortality increased in Canadians of European origin but remained constant or declined in those of south Asian and Chinese origin.
Substantial differences exist in rates of death from ischemic heart disease and cancer among European, south Asian and Chinese Canadians.
Canadian Medical Association Journal 08/1999; 161(2):132-8. · 5.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We examined seasonal variations in mortality from acute myocardial infarction (AMI) and stroke by age using 300,000 deaths in the Canadian Mortality Database for the years 1980 to 1982 and 1990 to 1992.
The effect of age on environmental determinants of AMI and stroke is not well understood.
Seasonal variations were analyzed by month and for the four seasons (winter beginning in December). A chi-square test was used to test for homogeneity at p < 0.01, and relative risk ratios (RRs) for high and low periods were determined in relation to the overall mean. For each of four age subgroups, the magnitude of the seasonal variation was reported as the difference in mortality between the highest and lowest frequency seasons.
By month, AMI deaths were highest in January (RR = 1.090) and lowest in September (RR = 0.904), a relative risk difference of 18.6%. The seasonal mortality variation in AMI deaths (winter vs. summer) increased with increasing age: 5.8% for <65, 8.3% for 65 to 74, 13.4% for 75 to 84 and 15.8% for >85 years (p < 0.005 for trend). Stroke mortality peaked in January (RR = 1.113) and had a trough in September (RR = 0.914), a relative risk difference of 19.9%. The seasonal variation in stroke mortality also increased with age. Seasonal variations were not seen in those aged <65 years, compared with 11.6% for 65 to 74, 15.2% for 75 to 84 and 19.3% for >85 years (p < 0.005 for trend).
The elderly demonstrate a greater winter increase in AMI and stroke mortality than younger individuals. An understanding of these seasonal patterns may provide novel avenues for research in cardiovascular disease prevention.
Journal of the American College of Cardiology 06/1999; 33(7):1916-9. · 15.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The study of ethnic differences in disease is a methodological challenge as ethnicity is often not identified in existing datasets and surrogate measures need to be used. We have developed a novel methodology combining last name and country of birth to study mortality patterns of Canadians of South Asian (SA) and Chinese (CH) ethnic origin and have compared death rates among SA, CH, and White (WH) Canadians.
SA and CH were identified in the Canadian Mortality Data Base (CMDB) using the last name and country of birth of the deceased. Records of people who had been born in countries with large South Asian and Chinese populations (e.g. India, Pakistan, China, Hong Kong) were selected and manually screened by last name. A name directory was then created of distinct South Asian and Chinese names and this directory was used to search all other records in the CMDB for SA and CH deaths. Where necessary, other identifying characteristics such as first name and parents' last name were also used. Population counts were obtained from the Census self-reported question on ethnicity for SA and CH. WH were identified as non-immigrant Canadians who were neither SA nor CH. The method of assigning ethnicity in the CMDB and Census were assessed for comparability and issues of validity and reliability were addressed.
Using this method, 10,989 SA and 21,548 CH deaths were identified. There was marked heterogeneity in birthplace, with only 56% of SA born in South Asia and only 74% of CH born in Greater China. Last names had high validity for self-reported ethnicity in a population sample of SA and were highly reproducible. Mortality rates varied dramatically between groups studied. SA and WH had high rates of ischemic heart disease while stroke mortality was similar among all three groups. Cancer death rates were high in CH and WH and much lower in SA.
Last names and country of birth can be used to determined ethnicity of SA and CH with validity and reliability, and leads to a more accurate classification than country of birth alone. The contrasting patterns observed in mortality from major causes of death suggest many interesting hypotheses for further study.
Ethnicity and Health 11/1997; 2(4):287-95. · 1.28 Impact Factor