Long-term incidence of pacemaker implantations and bradycardia among cross-country skiers

Background

Bradycardia is more common among well-trained athletes. The associations of training with pacemaker implantations are less known. We aim to investigate the association of endurance training with incidence of bradycardia and pacemaker implantations in a cohort of endurance athletes. Furthermore, we aim to establish potential sex differences of such associations.

Methods

Swedish skiers (209,072) that completed 1 or more races in the 30 to 90 km cross-country skiing event Vasaloppet (1989–2011) and a matched sample (n=531,949) of nonskiers were followed until first event of bradycardia or pacemaker implantation. The Swedish National Patient Register of in-patient and specialized outpatient care was used to obtain the date of diagnoses. Cox regression was used to investigate associations of number of completed races and finishing time with incidence of bradycardia and pacemaker implantations.

Results

Male skiers had higher incidence of bradycardia (hazard ratio [HR], 1.14; 95% CI, 0.99–1.30) and pacemaker implantations (HR, 1.14; 95% CI, 1.02–1.28) than male nonskiers. Male skiers completing most races or with the fastest finishing times had the highest incidence. The incidence of bradycardia (HR, 0.96; 95% CI, 0.70–1.30) and pacemaker implantations (HR, 0.97; 95% CI, 0.75–1.25) among female skiers in Vasaloppet was not different to that of female nonskiers. There was a trend that female skiers completing most races or with fastest finishing times had lower incidence.

Conclusions

Male skiers had higher incidence of bradycardia and pacemaker implantations. Female skiers in Vasaloppet had non-different incidence of bradycardia and pacemaker implantations. Men with the highest number of races and fastest finishing times had the highest incidence of pacemaker implantations. This indicates that bradycardia associated with training is not always as benign as previously suggested. The response appears to be different between sexes.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Uppsala UniversityCKF Dalarna

Prevalence of coronary atherosclerosis in individuals with pre-diabetes and diabetes compared to normoglycemic individuals

Background

Patients with type 2 diabetes have a two- to four-fold higher risk of death and cardiovascular events than the general population. Understanding the characteristics of atherosclerosis in people with different stages of dysglycaemia compared to normoglycaemic individuals may be useful for tailored prevention strategies in the future.

Purpose

To characterise the prevalence of coronary artery atherosclerosis in individuals with prediabetes, previously undetected diabetes and previously known diabetes compared with normoglycaemic individuals in a large population-based cohort.

Methods

Data were obtained from the Swedish CArdiopulumonary bioImage Study (SCAPIS), a population-based cohort of participants aged 50–64 years. The 25,553 study participants were categorised according to their glycaemic status: normoglycaemic (glucose: <6.1 mmol/L and HbA1c <6.0% (<42 mmol/mol)), pre-diabetes (6.1–6.9 mmol/L and/or elevated HbA1c 6.0–6.5% (42–47mmol/mol)), previously undetected diabetes (glucose ≥7.0 mmol/L and/or HbA1c >6.5% (≥48 mmol/mol)) or known diabetes. Plaque burden (number of diseased coronary segments) was determined by coronary computed tomography angiography (CCTA) in all 18 coronary artery segments. Total coronary artery atherosclerotic burden was assessed by segment involvement score (SIS) ≥4 and any coronary atherosclerosis. Imaging and analyses were performed using a calcium scoring protocol. The calcium content in each coronary artery was measured and summed to obtain an overall coronary artery calcification score (CACS).

Results

Study participants with dysclycaemia were defined as pre-diabetes (n=3,989, 16%), undetected diabetes (n=648, 2.5%) or known diabetes (n=1,033, 6.5%). The prevalence of CCTA-detected atherosclerosis among study participants, stratified by glycaemic status into four groups, is shown in Figure 1. The distribution of CACS categories by glycaemic status is shown in Figure 2. The association between CACS and glycaemic status, with normoglycemia as reference, was further explored in an adjusted (age, sex and site) ordinal regression: pre-diabetes 1.33 (95% CI 1.25–1.42), undetected diabetes 1.82 (95% CI 1.59–2.09), known diabetes 2.88 (95% CI 2.59–3.20). In a sensitivity analysis excluding people with previous myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention or with stent (n=693), the results were virtually unchanged, pre-diabetes 1.31 (95% CI 1.23–1.40), undetected diabetes 1.80 (95% CI 1.57–2.07), known diabetes 2.73 (95% CI 2.45–3.05).

Conclusions

The prevalence of coronary atherosclerosis increased substantially with increasing dysglycaemia. Our data suggest that more aggressive screening and/or treatment of individuals with prediabetes and diabetes to prevent cardiovascular disease should be discussed in the future.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The main funding body of The Swedish CArdioPulmonary bioImage Study (SCAPIS) is the Swedish Heart- and Lung Foundation.

Risk of aortic disease in long-distance cross-country skiers; a study of 209,226 patients

Background/Introduction

Aneurysmal dilatation and dissection of the aorta are two facets of aortic disease that can lead to major disability and death. Some risk factors for aortic disease are also risk factors for atherosclerotic disease, but the overall causes of aortic disease are diverse and largely unknown. Persons with aortic aneurysms are advised to limit their physical activity, but associations of physical activity with subsequent incidence of aortic disease are little known. Earlier studies have shown strong association of performance in Vasaloppet with incidence of hypertension, a major risk factor for aortic disease.

Aim

To investigate associations of high levels of physical activity with incidence of aortic disease.

Methods

We studied 209,226 participants in a 30–90 km cross-country skiing event (Vasaloppet) and 536,038 persons from the general population, matched to the skiers on age, sex and residence. The number of completed races during the study period and the fastest relative finishing time in a race was recorded. The main outcomes were: 1) aortic disease (defined as thoracic and abdominal aortic aneurysm and/or aortic dissection); and 2) aortic dissection.

Results

During a median time at risk of 8.8 years, 1,442 aortic disease events and 265 aortic dissections occurred. Skiers had lower incidence of aortic disease than non-skiers (Cox proportional hazards ratio [HR] 0.42; 95% confidence interval [CI] 0.36–0.50). An association of better finishing time with aortic disease was observed, with a dose-response gradient from the fastest third (HR 0.25; 95% CI 0.18–0.35), via the slowest third (HR 0.64; 95% CI 0.49–0.82) to the non-skiers (reference group). Among skiers the number of completed races was not associated with incidence of aortic disease. Skiers also had lower incidence of acute aortic dissection (HR 0.61; 95% CI 0.44–0.85) than non-skiers. Low event rate among skiers made conclusions in subgroups unreasonable. All results are adjusted for age, sex, education and income. Results were similar in models accounting for use of antihypertensive and cholesterol-lowering medicines and genetic syndromes associated with aortic disease.

Conclusion

Participation in a long-distance skiing event was associated with lower risk of aortic disease and aortic dissection. Faster completion of the race was strongly associated with lower incidence of aortic disease. If causal, this study suggests that high physical activity and exercise may be protective against aortic disease.

Kaplan-Meier Aorta disease

Funding Acknowledgement

Type of funding source: None

Blood pressure lowering treatment for prevention of cardiovascular events in patients with atrial fibrillation: an individual-participant data meta-analysis

Background

Randomised evidence showing that pharmacological blood pressure (BP) lowering can reduce cardiovascular risk of patients with atrial fibrillation (AF) is limited.

Purpose

This study aimed to compare the effect of BP-lowering treatment on fatal and non-fatal cardiovascular outcomes in patients with and without AF overall and by major drug classes.

Methods

We extracted individual participant data from all trials with over 1,000 person-years of follow-up that had randomly assigned patients to different classes of BP-lowering drugs, BP-lowering drugs vs placebo, or to more vs less intensive BP-lowering regimens. We investigated the effects of BP-lowering treatment on a composite endpoint of major cardiovascular events (stroke, ischaemic heart disease or heart failure) according to AF status at baseline using fixed-effect one-stage individual participant data meta-analyses based on Cox proportional hazards models stratified by trial.

Findings

Twenty-two trials were included with 188,570 patients, of whom 13,266 (7%) had AF at baseline. Patients with AF had lower BP at baseline than patients without AF (143/84 mmHg, SD 21/12mmHg) versus 155/88 mmHg, SD 21/13 mmHg, respectively). Meta-regression showed that relative risk reductions were proportional to trial-level intensity of BP lowering, both in patients with and without AF. The hazard ratio for major cardiovascular events was 0.91 in patients with AF (95% confidence interval [0.83–1.00]) and 0.91 without AF (95% confidence interval [0.88–0.93]) for each 5-mmHg reduction in systolic BP, with no difference between subgroups (p=0.91) (Figure 1). Similar patterns were observed for individual components of the composite primary outcome. In patients with AF, there was no evidence that treatment effects varied according to baseline systolic BP or use of specific drug classes.

Conclusion

This study demonstrated that BP-lowering treatment reduces the risk of major cardiovascular events in patients with AF to a similar extent to that of patients without AF, even when baseline BP is below recommended treatment thresholds. Owing to their higher absolute cardiovascular risk, treatment in patients with AF is likely to result in greater absolute risk reduction than in patients without AF. Guidelines should be updated to clearly recommend pharmacological BP lowering for prevention of cardiovascular events in patients with AF.

Figure 1. Forest plot

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation

Socioeconomic status, secondary prevention activities during the first year after a myocardial infarction and target attainments

Background

Socioeconomic status (SES) is a strong predictor of recurrent events post-myocardial infarction (MI) with unclear underlying mechanisms. To what extent SES is associated with secondary prevention activities (SPAs) and attainment of quality-of-care treatment goals is unknown.

Purpose

We aimed to assess the association between SES and SPAs during the first year post-MI and attained treatment targets at the 1-year follow-up.

Methods

Nationwide Swedeheart registry-based cohort study on 30,191 18–76 year old 11–15 month survivors of a first MI (8,180 women) 2006–2013. Complementary individual-level clinical data and data on SES (age and gender stratified quintiles of disposable income, level of education, and marital status), were linked from other national registries. Associations between SES and the outcomes were estimated in multivariable logistic regression models with basic adjustment for potential registry-related confounding.

Results

The associations between all indicators of SES and attendance to patient education and physical training programs were strong, moderate for dietary program attendance but absent for participation in smoking cessation program (Table 1). Higher SES was also associated with repeated lipid profile measurements and the highest vs lowest income with intensified statin therapy.

Correspondingly, higher SES was associated with having achieved target levels of LDL-C, blood pressure, and HbA1c as well as with persistence to and being on high intensity statin treatment (Figure 1). Further, higher SES was strongly associated with having quit smoking. No association with income was however observed regarding the weekly physical activity goal.

Conclusions

Higher SES was strongly associated with most SPAs including programs aiming at life style change and risk factor control as well as with attainment of corresponding secondary prevention targets. This may be explanatory for higher long-term risk of recurrent disease.

Figure 1. Target Attainment Forest Plots

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): Stockholm City Council and The Swedish Heart and Lung Association

Effect of blood pressure lowering treatment on the risk of atrial fibrillation: an individual-participant data meta-analysis

Background

Although observational studies have suggested an association between elevated blood pressure (BP) and increased risk of atrial fibrillation (AF), randomised evidence on the effects of pharmacological blood pressure lowering on the risk of new-onset AF remains limited.

Purpose

To investigate the effects of pharmacological BP lowering on the risk of AF overall and stratified by baseline risk of AF and by drug class.

Methods

We extracted individual participant data from trials with over 1,000 person-years of follow-up that had randomly assigned patients to different classes of BP-lowering drugs, BP-lowering drugs vs placebo, or to more vs less intensive BP-lowering regimens. We investigated the effects of BP lowering on the risk of new-onset AF using fixed-effect one-stage individual participant data meta-analyses based on Cox proportional hazards models stratified by trial.

Results

Twenty-one trials were included with a total of 194,041 patients, in whom 6,357 new-onset and 516 recurrent AF events were recorded. The hazard ratio for new-onset AF was 1.01, 95% CI [0.95–1.07] per each 5-mmHg reduction in systolic BP, and meta-regression suggested that treatment effects were similar irrespective of the intensity of systolic BP reduction. Patients were overall at low risk of AF at baseline (median 2.3%, IQR [1.2–3.4%] at 5 years), and there was no evidence of heterogeneity in treatment effects across thirds of risk and 10-mmHg strata of baseline systolic BP (Figure). There was also no clear evidence that treatment effects differed between drug classes when renin-angiotensin-aldosterone system inhibitors and calcium channel blockers were compared with placebo and/or standard treatment.

Conclusion

In a low-risk population, pharmacological BP lowering did not reduce the risk of new-onset AF. Further research is needed to understand whether the effects would be different in high-risk individuals, and to better clarify the existence of class-specific effects.

Figure 1. Forest plot

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation