The purpose of this study was to investigate the 5-year outcome following transcatheter aortic valve implantation (TAVI).
Little is known about long-term outcomes following TAVI.
The 5-year outcomes following successful TAVI with a balloon-expandable valve were evaluated in 88 patients. Patients who died within 30 days after TAVI were excluded.
Mean aortic valve gradient decreased from 46 ± 18 mm Hg to 10 ± 4.5 mm Hg after TAVI and 11.8 ± 5.7 mm Hg at 5 years (p for post-TAVI trend = 0.06). Mean aortic valve area increased from 0.62 ± 0.17 cm(2) to 1.67 ± 0.41 cm(2) after TAVI and 1.40 ± 0.25 cm(2) at 5 years (p for post-TAVI trend
Amiodarone is associated with dysfunction of the thyroid. Concerns have arisen regarding the potential for adverse effects with generic formulations of amiodarone. We evaluated and compared the risk of thyroid dysfunction between patients using brand-name versus generic formulations of amiodarone and identified risk factors for thyroid dysfunction.
We conducted a retrospective cohort study of patients with atrial fibrillation aged 66 years and older. We used administrative databases that linked information on demographics and clinical characteristics, claims for prescription drugs and discharges from hospital. We estimated thyroid dysfunction using person-year incidence.
Of the 60,220 patients in the cohort, 2804 (4.7%) used the brand-name formulation of amiodarone and 6278 (10.4%) used the generic formulation. Baseline characteristics between these two groups were comparable. The median maintenance dose of amiodarone was 200 mg/d for both groups. The total incidence rate for thyroid dysfunction was 14.1 per 100 person-years for both formulations. The mean time to clinical dysfunction of the thyroid was 4.32 years for the brand-name formulation and 4.09 years for the generic formulation. In a multivariate analysis, there was no significant difference in the incidence rates of thyroid dysfunction between the generic and brand formulations (hazard ratio 0.97, 95% confidence interval 0.87-1.08). Factors associated with an increased risk of thyroid dysfunction were being a woman, increasing age and having chronic obstructive pulmonary disease.
In this population-based study, we saw no difference between brand-name and generic formulations of amiodarone in terms of incidence of thyroid dysfunction.
The pharmacologic management of atrial fibrillation (AF), the most common sustained cardiac arrhythmia, has been traditionally dichotomized into control of ventricular rate or re-establishment and maintenance of sinus rhythm.
The purpose of this study was to evaluate the use of rate-controlling drugs and antiarrhythmic drugs (AAD) in the Canadian Registry of Atrial Fibrillation (CARAF) over a 16-year period from 1991 through 2007.
1,400 patients with new-onset paroxysmal AF who were enrolled in CARAF were included in this analysis. We assessed trends in ventricular rate-controlling medication use (digoxin, beta-blockers, and calcium channel blockers) and AAD (class IA, IC, and III antiarrhythmic agents) at baseline and follow-up visits as well as by calendar year.
AAD use increased initially from 1991 to 1994 (peak use 42.5%) before steadily declining. Sotalol use decreased (27% to 6%), whereas amiodarone use increased (1.6% to 17.9%). Rate-controlling medication use decreased from 1991 to 1995 (54.1% to 34.1%) due to declining digoxin use (62.9% to 16.3%). After 1999, there was a continued increase in rate-controlling medication use (peak use 52.5% in 2007) due to increased beta-blocker use (17% to 45.7%). Calcium channel blockers use changed little over the duration of the study.
The management of AF has undergone significant shifts since 1990, reflecting the influence of drug development, prevailing belief systems, the impact of large clinical trials, and evidence-based recommendations. Monitoring of pharmacotherapy trends will provide insight into the real-world application of evidence-based guidelines as well as allow the opportunity to identify deficiencies and improve patient care.
Despite the high prevalence of obesity and diabetes in the Canadian Aboriginal population, it is unknown whether the current thresholds for body mass index and waist circumference derived from white populations are appropriate for Aboriginal people. We compared the risk of cardiovascular disease among Canadian Aboriginal and European populations using the current thresholds for body mass index and waist circumference.
Healthy Aboriginal (n = 195) and European (n = 201) participants (matched for sex and body mass index range) were assessed for demographic characteristics, lifestyle factors, total and central adiposity and risk factors for cardiovascular disease. Among Aboriginal and European participants, we compared the relation between body mass index and each of the following 3 factors: percent body fat, central adiposity and cardiovascular disease risk factors. We also compared the relation between waist circumference and the same 3 factors.
The use of body mass index underestimated percent body fat by 1.3% among Aboriginal participants compared with European participants (p = 0.025). The use of waist circumference overestimated abdominal adipose tissue by 26.7 cm2 among Aboriginal participants compared with European participants (p = 0.007). However, there was no difference in how waist circumference estimated subcutaneous abdominal and visceral adipose tissue among the 2 groups. At the same body mass index and waist circumference, we observed no differences in the majority of cardiovascular disease risk factors among Aboriginal and European participants. The prevalence of dyslipidemia, hypertension, impaired fasting glucose and metabolic syndrome was similar among participants in the 2 groups after adjustment for body mass index, waist circumference, age and sex.
We found no difference in the relation between body mass index and risk of cardiovascular disease between men and women of Aboriginal and European descent. We also found no difference between waist circumference and cardiovascular disease risk among these groups. These data support the use of current anthropometric thresholds in the Canadian Aboriginal population.
Cites: Int J Obes Relat Metab Disord. 2000 Aug;24(8):1011-710951540
Cites: Am J Clin Nutr. 2007 Aug;86(2):353-917684205
Cites: JAMA. 2001 May 16;285(19):2486-9711368702
Cites: Lancet. 2001 Oct 6;358(9288):1147-5311597669
The effect of left atrial (LA) dimension on the recurrence of atrial fibrillation (AF) has been examined in small studies. We evaluated the effect of LA dimension on the occurrence of AF using 2- and 4-year echocardiographic data in a large cohort of patients with new onset AF.
The Canadian Registry of AF (CARAF) enrolled subjects with AF at the first electrocardiographically confirmed diagnosis. Patients were classified at 2 and 4 years as no recurrent AF (No RAF), paroxysmal AF (PAF), or chronic AF (CAF) based on clinical symptoms and electrocardiographic documentation. The association between baseline, 2-, and 4-year LA dimensions with occurrence of AF as determined by echocardiography was evaluated using a multivariate analysis.
The No RAF group (n = 176) had a significantly smaller LA dimension (36.9 +/- 6.8 mm) at baseline compared to the CAF group (n = 227) (42.8 +/- 7.5 mm, P
Comment In: Am Heart J. 2006 Feb;151(2):e1; author reply e316442883
Reimbursement for outpatient prescription drugs is not mandated by the Canada Health Act or any other federal legislation. Provincial governments independently establish reimbursement plans. We sought to describe variations in publicly funded provincial drug plans across Canada and to examine the impact of this variation on patients' annual expenditures.
We collected information, accurate to December 2006, about publicly funded prescription drug plans from all 10 Canadian provinces. Using clinical scenarios, we calculated the impact of provincial cost-sharing strategies on individual annual drug expenditures for 3 categories of patients with different levels of income and 2 levels of annual prescription burden ($260 and $1000).
We found that eligibility criteria and cost-sharing details of the publicly funded prescription drug plans differed markedly across Canada, as did the personal financial burden due to prescription drug costs. Seniors pay 35% or less of their prescription costs in 2 provinces, but elsewhere they may pay as much as 100%. With few exceptions, nonseniors pay more than 35% of their prescription costs in every province. Most social assistance recipients pay 35% or less of their prescription costs in 5 provinces and pay no costs in the other 5. In an example of a patient with congestive heart failure, his out-of-pocket costs for a prescription burden of $1283 varied between $74 and $1332 across the provinces.
Considerable interprovincial variation in publicly funded prescription drug plans results in substantial variation in annual expenditures by Canadians with identical prescription burdens. A revised pharmaceutical strategy might reduce these major inequities.
Cites: JAMA. 2001 Jan 24-31;285(4):421-911242426
Cites: Med Care. 2001 Apr;39(4):315-2611329519
Cites: Can J Public Health. 2001 Jul-Aug;92(4):307-1211962119
Cites: CMAJ. 2002 Aug 6;167(3):246-5212186169
Cites: Int J Health Serv. 2004;34(1):101-2215088676
Cites: N Engl J Med. 1991 Oct 10;325(15):1072-71891009
Cardiovascular disease (CVD) is the leading cause of mortality in women. In fact, CVD is responsible for a third of all deaths of women worldwide and half of all deaths of women over 50 years of age in developing countries. The prevalence of CVD risk factor precursors is increasing in children. Retrospective analyses suggest that there are some clinically relevant differences between women and men in terms of prevalence, presentation, management and outcomes of the disease, but little is known about why CVD affects women and men differently. For instance, women with diabetes have a significantly higher CVD mortality rate than men with diabetes. Similarly, women with atrial fibrillation are at greater risk of stroke than men with atrial fibrillation. Historically, women have been underrepresented in clinical trials. The lack of good trial evidence concerning sex-specific outcomes has led to assumptions about CVD treatment in women, which in turn may have resulted in inadequate diagnoses and suboptimal management, greatly affecting outcomes. This knowledge gap may also explain why cardiovascular health in women is not improving as fast as that of men. Over the last decades, mortality rates in men have steadily declined, while those in women remained stable. It is also becoming increasingly evident that gender differences in cultural, behavioural, psychosocial and socioeconomic status are responsible, to various degrees, for the observed differences between women and men. However, the interaction between sex-and gender-related factors and CVD outcomes in women remains largely unknown.
Cites: N Engl J Med. 2000 Apr 20;342(16):1187-9510770985
Cites: N Engl J Med. 2000 Apr 20;342(16):1207-1010770988
Radiofrequency ablation (RFA) has become an accepted therapy for atrial fibrillation (AF). The objective of this study was to perform an economic evaluation of RFA versus antiarrhythmic drug therapy (AAD) as first-line treatment of symptomatic paroxysmal AF.
To estimate and compare the costs of RFA versus AAD, a decision analytic model was developed using data on AF recurrence, hospitalization rates, AAD use, and treatment crossover rates derived directly from the Randomized Trial of RFA versus AAD as First-Line Treatment of Symptomatic Atrial Fibrillation (RAAFT). Resource utilization was modeled to reflect Canadian clinical practice in AF management. Unit costs of healthcare interactions were based on available Canadian government resources and published literature. Costs were assessed based on intention-to-treat. Total expected costs were computed to include initial treatment, hospital stay, physician fees, diagnostic tests, and outpatient visits. Sensitivity analyses were performed to account for the uncertainties. The study was conducted from the third party payer's perspective and costs are reported in 2005 Canadian dollars with 3% discount rate used in the analysis.
During the 2-month blanking period following therapy selection, total average costs for RFA and AAD were $10,465 and $2,556, respectively; at 1-year follow-up, these were $12,823 and $6,053; and total 2-year cumulative total average costs were $15,303 and $14,392. Sensitivity analyses did not alter the results, suggesting the model is robust.
RFA as first-line treatment strategy in patients with symptomatic paroxysmal AF was cost neutral 2 years after the initial procedure compared to AAD.
The structure of the Canadian health care system lends itself to health services and health outcomes research. It is possible to track hospital admissions and discharges, physician billings and prescriptions using administrative databases. In addition, several provinces have developed registries that provide detailed clinical and procedural information. Using the unique personal health numbers assigned to all Canadian residents, linkage between administrative databases and population-based clinical registries provides important information regarding the use of health services and health outcomes.
To determine the extent of cross-border (British Columbia-Alberta border) use of cardiac services by British Columbia residents.
Population rates of cardiac procedures were calculated using two prospective clinical registries (British Columbia Cardiac Registries and Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease [APPROACH]), as well as administrative databases (the British Columbia Ministry of Health's hospitalization and Medical Services Plan databases).
Analyses using only British Columbia data suggest low cardiac procedure rates for patients living in eastern British Columbia. By accessing APPROACH data, it was determined that more than 80% of British Columbia cardiac patients living along the British Columbia-Alberta border access procedural services in Alberta.
While residents of eastern British Columbia appear to have reduced access to cardiac services when data from British Columbia are analyzed in isolation, they are actually accessing care in Alberta. Analyses based solely on single province data sources will underestimate cardiac procedures rates.
Recent research has identified younger women as an "at-risk" population with rising prevalence of cardiac risk factors and excess mortality risk following acute myocardial infarction (AMI). However, population-based data on trends in AMI hospitalization and early mortality post AMI among younger adults is scarce. We, therefore, aimed to provide a 10-year, descriptive analysis of these trends in a Canadian setting.
We assessed trends and sex differences in AMI hospitalization and 30-day mortality rates using negative binomial and logistic regression, respectively. From 2000 to 2009, there were 70,628 AMI hospitalizations in adults aged =20 years, in British Columbia, Canada, with 17.1% of cohort being younger adults =55 years. Overall, age-standardized AMI rates (per 100,000 population) declined similarly in men (295.8 to 247.7) and women (152.1 to 128.8) [sex-year interaction p=0.81]. However, these trends differed according to age (age-sex-year interaction p=0.02) with increased rates observed only in younger women (+1.7% per year; p=0.04). The 30-day mortality rates declined similarly for women (19.4% to 13.9%) and men (13.0% to 9.3%) (sex-year interaction p=0.33). Yet, younger women continued to have excess mortality risk, compared with younger men, even in the most recent period [odds ratio: (2008-09)=1.61 (95% onfidence interval: 1.25, 2.08)].
While the overall AMI hospitalization and 30-day mortality rates significantly declined in women and men, hospitalization rates in women =55 years increased and their excess risk of 30-day mortality persisted. These findings highlight the need to intensify strategies to reduce the incidence of AMI and improve outcomes after AMI in younger women.