Another life-sav­ing ap­pli­ca­tion for beta block­ers

Oral drug used for long-term treat­ment of heart dis­ease may also help af­ter at­tack

Toronto Star - - LIFE - MICHELE HENRY STAFF RE­PORTER

Long-hailed su­per­drug for treat­ing chronic heart dis­ease, beta block­ers may have another life-sav­ing ef­fect on the or­gan, new re­search sug­gests.

A team of sci­en­tists at York Univer­sity has dis­cov­ered that this class of drugs, con­sid­ered mirac­u­lous for eas­ing the work­load of a dam­aged, but func­tion­ing heart, may also help the or­gan’s mus­cle cells sur­vive an acute at­tack.

Dam­age and death of the car­diomy­ocyte, which con­tract to make the heart pump, could lead to heart fail­ure.

“This is a new as­pect of beta-blocker func­tion that wasn’t known be­fore,” says York Univer­sity depart­ment of bi­ol­ogy pro­fes­sor John McDer­mott, the study’s lead au­thor.

“It’s ex­cit­ing to have a po­ten­tial ap­pli­ca­tion of one of the dis­cov­er­ies we’ve made.”

Cur­rently, doc­tors only pre­scribe beta block­ers as a long-term treat­ment for heart dis­ease. It’s not used in crit­i­cal or acute care.

But the study, pub­lished this month in the jour­nal Cell Death Dis­cov­ery, sug­gests that an im­me­di­ate dose of beta block­ers in the hours fol­low­ing a heart at­tack could stop these cru­cial cells from dy­ing in the short term — and down the road.

The beta block­ers, which are taken orally, slow heart rate and ease pres­sure on a strug­gling cir­cu­la­tory sys- tem, en­abling a dam­aged heart to con­tinue to do its duty.

Now, it ap­pears that in rat and mouse tis­sue, these drugs pro­mote the ac­tiv­ity of Mef2, a pro­tein mol­e­cule found in the heart’s mus­cle. Mef2 pro­tects cells, which have be­come stressed in one way or another, from dy­ing, McDer­mott says.

That is vi­tal be­cause heart cells can’t re­gen­er­ate.

And they be­come par­tic­u­larly vul­ner­a­ble dur­ing a heart at­tack when a surge of hor­mones, par­tic­u­la­drenali­naline, block Mef2’s pro­tec­tive ac­tion, he says.

McDer­mott’s team dis­cov­ered that the beta block­ers seem to block those ne­far­i­ous hor­monal sig­nals, en­abling Mef2 to con­tinue its im­por­tant work of help­ing the heart’s mus­cle cells stay alive and op­er­at­ing smoothly.

“If you lose those (heart mus­cle) cells, you can’t get them back,” he says. “And then the heart can’t func­tion very well to push blood around your body.”

The next step in the re­search, McDer­mott says, is to find out whether the beta block­ers have the same ef­fect on hu­man tis­sue as they do in the ro­dent cells.

McDer­mott, who has been study­ing mus­cle gene ex­pres­sion for more than 25 years, has re­cently col­lab­o­rated with a re­search group at the Toronto Gen­eral Hos­pi­tal, which stud­ies hu­man heart tis­sue.

If all goes well, he says, it may not be too long be­fore beta block­ers, which are well tested and have been widely pre­scribed since the 1970s, are used in this new ap­pli­ca­tion.

DREAMSTIME

Beta block­ers have a long history of treat­ing chronic heart dis­ease.

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