Hugues Richard

Cancer risk related to low-dose ionizing radiation from cardiac imaging in patients after acute myocardial infarction

Background Patients exposed to low-dose ionizing radiation from cardiac imaging and therapeutic procedures after acute myocardial infarction may be at increased risk of cancer. Methods Using an administrative database, we selected a cohort of patients who had an acute myocardial infarction between April 1996 and March 2006 and no history of cancer. We documented all cardiac imaging and therapeutic procedures involving low-dose ionizing radiation. The primary outcome was risk of cancer. Statistical analyses were performed using a time-dependent Cox model adjusted for age, sex and exposure to low-dose ionizing radiation from noncardiac imaging to account for work-up of cancer. Results Of the 82 861 patients included in the cohort, 77% underwent at least one cardiac imaging or therapeutic procedure involving low-dose ionizing radiation in the first year after acute myocardial infarction. The cumulative exposure to radiation from cardiac procedures was 5.3 milliSieverts (mSv) per patient-year, of which 84% occurred during the first year after acute myocardial infarction. A total of 12 020 incident cancers were diagnosed during the follow-up period. There was a dose-dependent relation between exposure to radiation from cardiac procedures and subsequent risk of cancer. For every 10 mSv of low-dose ionizing radiation, there was a 3% increase in the risk of age- and sex-adjusted cancer over a mean follow-up period of five years (hazard ratio 1.003 per milliSievert, 95% confidence interval 1.002–1.004). Interpretation Exposure to low-dose ionizing radiation from cardiac imaging and therapeutic procedures after acute myocardial infarction is associated with an increased risk of cancer.

Differences in outcomes of patients with congestive heart failure prescribed celecoxib, rofecoxib, or non-steroidal anti-inflammatory drugs: population based study

Abstract Objectives To compare the risk of death and recurrent congestive heart failure in elderly patients prescribed celecoxib, rofecoxib, or non-steroidal anti-inflammatory drugs (NSAIDs) and to determine whether there are class differences between celecoxib and rofecoxib. Design Population based retrospective cohort study. Setting Databases of hospital discharge summaries and prescription drug claims in Quebec. Participants 2256 patients aged 66 or more prescribed celecoxib, rofecoxib, or an NSAID after an index admission for congestive heart failure between April 2000 and March 2002. Main outcome measures Time to all cause death and recurrent congestive heart failure, combined and separately. Results The risk of death and recurrent congestive heart failure combined was higher in patients prescribed NSAIDs or rofexocib than in those prescribed celecoxib (hazard ratio 1.26, 95% confidence interval 1.00 to 1.57 and 1.27, 1.09 to 1.49, respectively). The findings were similar when the outcomes were assessed separately. In pairwise analysis, the risks of death and recurrent congestive heart failure, combined and separate, were similar between patients prescribed NSAIDs and rofecoxib. Conclusions Celecoxib seems safer than rofecoxib and NSAIDs in elderly patients with congestive heart failure. Differences were found among cyclo-oxygenase-2 inhibitors.

Life-Course Socioeconomic Position and Incidence of Coronary Heart Disease The Framingham Offspring Study

Cumulative exposure to socioeconomic disadvantage across the life course may be inversely associated with coronary heart disease (CHD); the mechanisms are not fully clear. An objective of this study was to determine whether cumulative life-course socioeconomic position (SEP) is associated with CHD incidence in a well-characterized US cohort that had directly assessed childhood and adulthood measures of SEP and prospectively measured CHD incidence. Furthermore, analyses aimed to evaluate whether adjustment for CHD risk factors reduces the association between cumulative life-course SEP and CHD. The authors examined 1,835 subjects who participated in the Framingham Heart Study Offspring Cohort from 1971 through 2003 (mean age, 35.0 years; 52.4% women). Childhood SEP was measured as fathers education; adulthood SEP was assessed as own education and occupation. CHD incidence included myocardial infarction, coronary insufficiency, and coronary death. Cox proportional hazards analyses indicated that cumulative SEP was associated with incident CHD after adjustment for age and sex (hazard ratio = 1.82, 95% confidence interval: 1.17, 2.85 for low vs. high cumulative SEP score). Adjustment for CHD risk factors reduced that magnitude of association (hazard ratio = 1.29, 95% confidence interval: 0.78, 2.13). These findings underscore the potential importance of CHD prevention and treatment efforts for those whose backgrounds include low SEP throughout life.

Comparative Effectiveness of Rhythm Control vs Rate Control Drug Treatment Effect on Mortality in Patients With Atrial Fibrillation

BACKGROUND Controversy continues concerning the choice of rhythm control vs rate control treatment strategies for atrial fibrillation (AF). A recent clinical trial showed no difference in 5-year mortality between the 2 treatments. We aimed to determine whether the 2 strategies have similar effectiveness when applied to a general population of patients with AF with longer follow-up. METHODS We used population-based administrative databases from Quebec, Canada, from 1999 to 2007 to select patients 66 years or older hospitalized with an AF diagnosis who did not have AF-related drug prescriptions in the year before the admission but received a prescription within 7 days of discharge. Patients were followed until death or administrative censoring. Mortality was analyzed by multivariable Cox regression. RESULTS Among 26,130 patients followed for a mean (SD) period of 3.1 years (2.3 years), there were 13,237 deaths (49.5%). After adjusting for covariates, we found that the effect of rhythm vs rate control drugs changed over time: after a small increase in mortality for patients treated with rhythm control in the 6 months following treatment initiation (hazard ratio [HR], 1.07; 95% CI, 1.01-1.14), the mortality was similar between the 2 groups until year 4 but decreased steadily in the rhythm control group after year 5 (HR, 0.89; 95% CI, 0.81-0.96; and HR, 0.77; 95% CI, 0.62-0.95, after 5 and 8 years, respectively). CONCLUSIONS In this population-based sample of patients with AF, we found little difference in mortality within 4 years of treatment initiation between patients with AF initiating rhythm control therapy vs those initiating rate control therapy. However, rhythm control therapy seems to be superior in the long-term.

Gout, Allopurinol Use, and Heart Failure Outcomes

BACKGROUND Hyperuricemia is associated with reduced survival among patients with heart failure (HF), but the effect of gout on HF outcomes is unknown. A recent randomized trial suggested that allopurinol may reduce adverse outcomes among patients with hyperuricemia and HF. Our objective was to determine whether gout and allopurinol use are associated with HF outcomes. METHODS Time-matched, nested case-control analysis of a retrospective cohort of patients with HF who were 66 years or older using health care databases in Quebec, Canada. The primary outcome measure was a composite measure of HF readmission and all-cause mortality. The secondary outcome measure was all-cause mortality. Rate ratios were calculated using conditional logistic regression and adjusted for known prognostic factors. RESULTS Of the 25,090 patients in this cohort, 14,327 experienced the primary outcome. Both a remote history of gout and an acute episode of gout (within 60 days of the event date) were associated with an increased risk of HF readmission or death (adjusted rate ratio, 1.63; 95% confidence interval, 1.48-1.80; P<.001 and 2.06; 1.39-3.06; P<.001, respectively). Continuous allopurinol use (>30 days of continuous use) was not associated with the primary outcome among the overall population with HF (adjusted rate ratio, 1.02; 95% confidence interval, 0.95-1.10; P=.55) but was associated with reduced HF readmissions or death (0.69; 0.60-0.79; P<.001) and all-cause mortality (0.74; 0.61-0.90; P<.001) among patients with a history of gout. CONCLUSIONS Patients with HF and a history of gout represent a high-risk population. Among such patients, the use of allopurinol is associated with improved outcomes.

Impact of on-site cardiac catheterization on resource utilization and fatal and non-fatal outcomes after acute myocardial infarction

BackgroundPatterns of care for acute myocardial infarction (AMI) strongly depend on the availability of on-site cardiac catheterization facilities. Although the management found at hospitals without on-site catheterization does not lead to increased mortality, little it known about its impact on resource utilization and non-fatal outcomes.MethodsWe identified all patients (n = 35,289) admitted with a first AMI in the province of Quebec between January 1, 1996 and March 31, 1999 using population-based administrative databases. Medical resource utilization and non-fatal and fatal outcomes were compared among patients admitted to hospitals with and without on-site cardiac catheterization facilities.ResultsCardiac catheterization and PCI were more frequently performed among patients admitted to hospitals with catheterization facilities. However, non-invasive procedures were not used more frequently at hospitals without catheterization facilities. To the contrary, echocardiography [odds ratio (OR), 2.04; 95% confidence interval (CI), 1.93–2.16] and multi-gated acquisition imaging (OR, 1.24; 95% CI, 1.17–1.32) were used more frequently at hospitals with catheterization, and exercise treadmill testing (OR, 1.02; 95% CI, 0.91–1.15) and Sestamibi/Thallium imaging (OR, 0.93; 95% CI, 0.88–0.98) were used similarly at hospitals with and without catheterization. Use of anti-ischemic medications and frequency of emergency room and physician visits, were similar at both types of institutions. Readmission rates for AMI-related cardiac complications and mortality were also similar [adjusted hazard ratio, recurrent AMI: 1.02, 95% CI, 0.89–1.16; congestive heart failure: 1.02; 95% CI, 0.90–1.15; unstable angina: 0.93; 95% CI, 0.85–1.02; mortality: 0.99; 95% CI, 0.93–1.05)].ConclusionAlthough on-site availability of cardiac catheterization facilities is associated with greater use of invasive cardiac procedures, non-availability of catheterization did not translate into a higher use of non-invasive tests or have an impact on the fatal and non-fatal outcomes available for study in our administrative database.