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JUST 30 MINUTES : Dramatic Decrease in AF With Cardio Fitness

Exercise shown to have some AFib-specific benefits.  

Atrial fibrillation (AF) is associated with increased mortality risk. The risk for AF increases for individuals with hypertension (HTN) and type 2 diabetes mellitus (DM). Little is known about the association between fitness and AF in hypertensive and individuals with diabetes. The researchers assessed the AF-fitness association in patients with DM and HTN.

For the current analysis, the investigators sought to examine a possible association between fitness and AF risk in individuals who specifically had hypertension and/or diabetes because little has been known about this high-risk group.

From 1986 to 2012, over 12,000 individuals underwent a routine exercise test at the Veterans Affairs Medical Center in Washington, DC. Of these, 4,065 were identified as hypertensive and/or individuals with diabetes (mean age 59), with normal sinus rhythm and ET response. They formed four fitness categories based on age-adjusted peak workload achieved (METs): Least-Fit: (5.0 1.0 METs (25%; n ¼ 1,117); Low-Fit: 6.5 1.0 METs (25.1%-50%; n ¼ 1,091); Moderate-Fit: 7.8 1.0 METs (50.1%-75%; n ¼ 1,044); and High-Fit: 9 1.1 METs (>75%; n¼ 813).

The new research shows that cardiorespiratory fitness is associated with a progressively lower risk of atrial fibrillation in middle-aged men with diabetes or hypertension. Plus, exercising can have some AFib-specific benefits, including slowing your heart rate and lowering your blood pressure.

In the study of more than 4,000 hypertensive and/or diabetic veterans who didn’t have AF at baseline, there was a 29% lower risk of AF occurrence for every one-unit increase in peak metabolic equivalent of tasks (MET). A larger study from the investigators was published in the May 2016 issue of Mayo Clinical Proceedings. It included 5,962 veterans, but did not split out patient information on hypertension and diabetes.

In this study, the risk was lowered by 58% in those considered “moderately fit” and by 74% in those considered “highly fit” compared with the least-fit group. Just 10-15 minutes a day can have a 30% lower risk of AF.

“These fitness levels are achievable through moderate daily exercise and physical activity. Just 30 minutes of a brisk walk regularly can really make a difference,” researchers noted, as the results were presented at the American Society of Hypertension (ASH) 2016 Annual Scientific Meeting.

Within 8.3 years, 12% of the participants developed AF; but the risk was 21% lower for each 1-MET increase in exercise capacity. Those at the highest fitness level had an HR of just 0.37, those at the next level down had an HR of 0.55, and those at the third level down had an HR of 0.80 vs those who were at the lowest fitness level.

Slow fitness is what you get (5 METs) when cutting grass or climbing stairs  The 6.5 happens when people are active somewhat on a daily basis, the moderate-fit are probably walking three times a week, and then the high-fit are walking four to five times a week and maybe doing a little speed walking on the side, nothing too extreme.

Results showed that within 8+4.7 years of follow-up, 8.9% of the entire cohort had AF.

Compared with those in the least-fit group, the HRs were 0.26 for the high-fit group (95% CI 0.18–0.37), 0.42 for the moderate fit (95% CI 0.31–0.58), and 0.70 for the low fit (95% CI 0.55–0.90) after adjustment for a wide list of factors, including age, race, and history of CV disease.

From the results, it was concluded that cardiorespiratory fitness is inversely and independently associated with lower AF risk.

We still need to be aware of the possible side effects of exercising with AF. One of the common symptoms associated with AF is tiring more easily when you exercise, and others include, heart palpitations, dizziness, sweating, anxiety and shortness of breath.

They also discovered that the risk reduction found in the high-risk group “was huge” and the 9 METs they achieved is achievable.

So from the results it was concluded that cardiorespiratory fitness is inversely and independently associated with lower risk for developing AF in diabetic or hypertensive individuals.

Practice Pearls:

  • Risk for AF increases for individuals with hypertension (HTN) and type 2 diabetes mellitus (DM).
  • Too little or too much exercise may be the “sweet spots” for increased AF risk.
  • Cardiorespiratory fitness is inversely and independently associated with lower AF risk in this cohort.

 

Kokkinos P, Faselis C, Tsimploulis A, et al. Exercise capacity and risk of new onset of a-fib in hypertensive and diabetic patients. American Society of Hypertension 2016 Annual Scientific Meeting; May 14, 2016; New York, NY. Abstract PF-5