Aerobic Training Reverses Left-Ventricular Remodeling in Stable Heart Failure

[Guest guest]

The following should be very interesting and I suspect

somewhat controversial for this group.

Ralph Giarnella MD

Southington Ct USA

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Aerobic Training Reverses Left-Ventricular Remodeling

in Stable Heart Failure

By Peggy Peck, Managing Editor, MedPage Today

Reviewed by Jasmer, MD; Associate Clinical

Professor of Medicine, University of California, San

Francisco

June 13, 2007

Add Your Knowledge™ Additional CHF Coverage

EDMONTON, Alberta, June 13 -- For patients with stable

heart failure, cardiac rehabilitation that focuses on

aerobic training can reverse left-ventricular

remodeling and improve ejection fraction.

Action Points

Explain to interested patients that cardiac

rehabilitation has been show to be beneficial in

several studies, but this study suggests that aerobic

exercise programs may be superior to strength training

for heart failure patients with stable disease.

That finding emerged from a meta-analysis of 14

randomized controlled trials of exercise training in

patients with heart failure published in the June 19

issue of the Journal of the American College of

Cardiology.

Aerobic training significantly improved ejection

fraction by a weighted mean difference of 2.59% (95%

CI 1.44%-3.74%) at the same time that it significantly

reduced end systolic volume and end diastolic volume,

wrote Mark J. Haykowsky, Ph.D., of the University of

Alberta here, and colleagues.

There was, however, no confirmed benefit for combining

aerobic and strength training.

The 14 trials included clinically stable patients with

heart failure symptoms and a weighted mean ejection

fraction of 23% at baseline. The mean age of patients

was 57, and 89% of the patients were men.

Nine of the trials studied aerobic exercise training,

usually at 60% to 80% of baseline VO2 peak, and four

investigated combined aerobic and strength training

regimens. One study investigated strength training

alone.

The authors noted that when the findings of all trials

were pooled, exercise training was associated with " a

significant improvement in [ejection fraction] " but

the analysis demonstrated substantial heterogeneity.

However, when the results of the aerobic trials were

analyzed separately those results demonstrated

" relatively consistent benefits " in the heart's

pumping capacity for the 538 patients who

participated.

The finding that strength training was not beneficial

was unexpected, but the authors speculated that it

might be due to " the heightened systolic and diastolic

pressure loading that occurs with strength training.

Moreover, the strength-training-mediated increase in

LV wall stress, coupled with impaired contractile and

preload reserve, could explain why LV stroke volume

and [ejection fraction] do not increase with this type

of exercise. "

And while aerobic training was found to be beneficial,

the authors could only speculate as to why this was so

suggesting that " it may be due to the reduction in

vasoconstrictive neurohormones or a decline in

hemodynamic loading. "

But the take home message was unambiguous-aerobic

training is " an inexpensive and effective nondrug,

nondevice, nonsurgical intervention that reverses

ventricular remodeling and improves VO2 peak in

clinically stable individuals with [heart failure] and

LV systolic dysfunction. "