Running: The Risk of Coronary Events: Prevalence and Prognostic Relevance of Coronary Atherosclerosis in Marathon Runners

Stefan Möhlenkamp; Nils Lehmann; Frank Breuckmann; Martina Bröcker-Preuss; Kai Nassenstein; Martin Halle; Thomas Budde; Klaus Mann; Jörg Barkhausen; Gerd Heusch; Karl-Heinz Jöckel; Raimund Erbel

Disclosures

Eur Heart J. 2008;29(15):1903-1910. 

In This Article

Results

One hundred and eight male runners aged 50-72 years were included in the study. They had completed 20 marathons (median value, Q1-Q3: 14-42), had started marathon running nine years ago (Q1-Q3: 7-16), and trained 55 km (approximately 35 miles) (Q1-Q3: 45-65) on five days per week throughout the year.

Matching

Our attempt to match two males out of 1597 eligible males from the HNRS with each marathon runner by age, BMI, and FRS did not result in an equal FRS but in a lower FRS in marathon runners than in group-III controls (7.0 ± 3.6 vs. 7.7 ± 3.4%, P = 0.03) ( Table 1 ).

Risk Factor Distribution

Compared with age-matched controls, marathon runners had a 42% higher high-density lipoprotein cholesterol, an 18% lower low-density lipoprotein-cholesterol, a 19% lower rate of ever smoking, a 12% lower systolic blood pressure, and a 15% lower BMI ( Table 1 ), resulting in a 51% lower mean 10 year FRS (7.0 ± 3.6 vs. 14.3 ± 8.2%, P < 0.0001).

Physical Activity

Marathon runners had higher weekly metabolic equivalents (METs) and lower heart rates than both control groups ( Table 1 ). We found no age-adjusted Spearman correlation between weekly METs and CAC in marathon runners (R 2 = 0.02, P = 0.13) or in age-matched controls (R 2 = 0.001, P = 0.36). In marathon runners, CAC was also not associated with years of running (R 2 = 0.024, P = 0.12), with the number of marathon races completed (R 2 = 0.007, P = 0.39), or with training mileage (R 2 = 0.014, P = 0.23). Regression analyses revealed no hints for curve-linearity in any of these relations, and the respective 95% confidence intervals (CIs) of estimated slopes all included zero.

Prevalence and Extent of Coronary Artery Calcification

A zero CAC score was more frequent in marathon runners than in age-matched controls, but was similar when compared with FRS-matched controls ( Table 2 ). The overall CAC score distribution was similar in marathon runners and age-matched controls ( Table 2 ) with similar rates of CAC ≥ 100 in these groups (36.1 vs. 36.3%, P = 0.96) but higher rates in marathon runners when compared with FRS-matched controls (36.1 vs. 21.8%, P = 0.01) ( Table 2 ).

Prevalence and Predictors of Myocardial Late Gadolinium Enhancement

cMRI studies were performed in 102 subjects. Reasons for non-participation were a cochlear metal implant (n = 1), metal splinter in a rib (n = 1), claustrophobia (n = 1), refusal of contrast administration (n = 2), and poor image quality (n = 1). LGE was observed in 12 persons (12%) with n = 5 (42%) showing a subendocardial scar pattern typical of ischaemia and n = 7 (58%) with a mid-myocardial patchy pattern suggesting non-ischaemic origin. Runners with LGE had a higher CAC score vs. those without LGE [median CAC (Q1-Q3): 192 (129-603) vs. 26 (0-159), P = 0.0046]. In univariate analysis, the CAC score, CAC percentile values, and the number of marathons but not the FRS were associated with LGE ( Table 3 ). In multivariable analysis, CAC percentile distribution and the number of marathons remained independently associated with the presence of LGE ( Table 3 ). These associations were confirmed by exact logistic regression.

Follow-up and Events

No marathon runner died during 21.0 months [interquartile range (IQR) 18.6-24.0 months) of follow-up. Coronary events occurred in four runners ( Table 4 ). Two of these were sudden (hard) coronary events and two others were revascularizations. The first runner with an event (CAC = 874, Table 4 ) was successfully resuscitated after 7 km during a 10 km race. Coronary angiography revealed significant stenoses (>80% lumen reduction) in all three vessels. The second runner with an event (CAC = 472, Table 4 ) underwent uneventful coronary artery bypass graft (CABG) surgery because of left main disease and significant angiographic two-vessel disease, which was identified during additional testing, as previously published in detail.[11] Revascularization in the third event (CAC = 171, Table 4 ) was triggered by an electrocardiogram (EKG) performed after a marathon competition demonstrating ST-elevation. A subsequent echocardiogram showed septal wall motion abnormality, which was followed by invasive angiography, demonstrating significant left anterior descending stenosis and myocardial bridging of a septal branch. The fourth event (CAC = 128, Table 4 ) occurred just after moderate physical exercise. The participant was successfully resuscitated. Coronary angiography demonstrated significant three-vessel disease followed by CABG surgery. At present, all these runners are fit and well.

Distribution of CAC in runners with events was as follows -- CAC <100: 0 of 69 (0%); CAC 100 to <400: two of 25 (8%), and CAC ≥400: two of 14 (14.3%). The difference in event rates among CAC groups reached statistical significance using log-rank analysis but just failed to reach statistical significance using Cox regression analysis (Figure 1).

Figure 1.

Kaplan-Meier estimates of event-free survival by extent of coronary artery calcification (CAC). No marathon runners with CAC <100 experienced a coronary event, while 8% and 14.3% of those with CAC 100 to <400 and ≥400, respectively, required revascularization during follow-up. Using Cox regression analysis, hazard ratios for a two-fold increase in log2(CAC+1) were: hazard ratio = 1.51, 95% confidence interval = 0.97-2.36, P = 0.07. The numbers pertain to the subjects with events in Table 3 .

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