Doc­tor from Stel­lar­ton prob­ing heart health

Lynn Me­geney hopes to use find­ings to de­velop treat­ment for pa­tients

The News (New Glasgow) - - FRONT PAGE - BY SAM MACDON­ALD

A doc­tor with roots in Pic­tou County is well on the way to help­ing peo­ple who suf­fer from heart dis­ease, with “game-chang­ing” new sci­en­tific find­ings.

Lynn Me­geney, born and raised in Stel­lar­ton, is one of sev­eral sci­en­tists at the cusp of a break­through in the sci­ence be­hind treat­ing heart dis­ease.

Me­geney, a se­nior sci­en­tist at the Ot­tawa Hospi­tal Re­search In­sti­tute and pro­fes­sor in the De­part­ment of Medicine at the Uni­ver­sity of Ot­tawa, has been work­ing to un­cover the re­gen­er­a­tive po­ten­tial of a par­tic­u­lar heart pro­tein called car­diotrophin 1 (CT-1).

“We’ve known for a long time, that there are many ben­e­fits to be de­rived from reg­u­lar ex­er­cise for the heart,” said Me­geney. “The heart adapts in a spe­cific way to reg­u­lar pat­terns of ac­tiv- ity and ex­er­cise. It gets big­ger and thicker, and the blood sup­ply dra­mat­i­cally im­proves its abil­ity to work as a pump im­proves with ex­er­cise.”

Me­geney and his fel­low sci­en­tists have been able to de­ter­mine that CT-1 plays an im­por­tant role in the process of strength­en­ing a heart.

In his re­search, Me­geney dis­cov­ered that the same pro­tein that helps en­durance ath­letes’ hearts grow stronger from reg­u­lar train­ing is the same one that causes a preg­nant woman’s heart to grow in size and strength as her preg­nancy pro­gresses.

“It’s quite re­mark­able – a woman who de­liv­ers a baby has a heart mass that in­creases 30 to 35 per cent. The in­ter­est­ing thing about that type of change in the heart is that it is fully re­versible,” Me­geney said. “If some­one stops train­ing, their heart will re­turn to nor­mal di­men­sions and a preg­nant woman’s heart will be back to its nor­mal size, three to four months af­ter hav­ing a baby.”

Me­geney said that was a premise of over a decade of re­search he and his col­leagues did — find­ing out how pro­teins and genes fac­tor into that chang­ing heart size, since that “raises the pos­si­bil­ity that some­thing is go­ing on, that drives this pos­i­tive change.”

Much of the work has been find­ing fac­tors to use in sit­u­a­tions where the heart is not work­ing well, to bring it back to a more func­tional state.

“We want to fig­ure out how to in­cor­po­rate the ben­e­fi­cial sorts of changes of CT-1, like mak­ing the heart and cells big­ger, and im­prov­ing the blood sup­ply,” said Me­geney.

This couldn’t come at a bet­ter time, since heart dis­ease – par­tic­u­larly right heart fail­ure, a con­di­tion for which very few treat­ment op­tions ex­ist – is on the rise in the de­vel­oped world, par­tic­u­larly North Amer­ica.

“There’s a divi­sion in the pa­tient pop­u­la­tion right now. We be­came good at treat­ing con­ges­tive heart fail­ure. Those pa­tients get drugs that put the brakes on pro­gres­sion of heart fail­ure — we’re good at man­ag­ing that kind of heart fail­ure,” said Me­geney.

Right heart fail­ure, on the other hand, is a dif­fer­ent story. About 45 to 50 per cent of pa­tients di­ag­nosed with heart fail­ure suf­fer from right heart fail­ure — a con­di­tion that the litany of drugs avail­able for con­ges­tive heart fail­ure are in­ef­fec­tive at treat­ing.

“What we saw with car­diotrophin is that it can ben­e­fi­cially re­model the right side of the heart, like preg­nant women’s and ath­letes’ hearts. Car­diotrophin is ef­fec­tive in re­pro­duc­ing the ef­fect of ex­er­cise in pa­tients,” said Me­geney.

“It could put the brakes on some­thing like right heart fail­ure, and stop it right in its tracks.”

This is nec­es­sary, Me­geney said, be­cause other med­i­cal in­ter­ven­tions, short of a heart trans­plant, don’t work at treat­ing right heart fail­ure. And with be­tween 100,000 and 300,000 pa­tients suf­fer­ing from right heart fail­ure, per year in North Amer­ica, the prob­lem con­tin­ues to grow – es­pe­cially as the pop­u­la­tion con­tin­ues to age.

“There are a lot of fac­tors. We don’t un­der­stand all of them yet, but the only in­ter­ven­tion pa­tients have as an op­tion right now is a heart trans­plant. There aren’t 100,000 to 300,000 hearts avail­able for trans­plant, so it’s a huge med­i­cal need to treat the is­sue.”

At this stage, Me­geney said he is oc­cu­pied work­ing on pre-clin­i­cal tri­als on mice and rats — and those tri­als are go­ing well. Doses of hu­man CT-1 have been demon­strated to “put the brakes on” right heart fail­ure.

The fact that tri­als in­volve the hu­man pro­tein be­ing used on an­i­mals gives Me­geney and his col­leagues “a leg up in de­vel­op­ment of this for pa­tient pop­u­la­tions.”

He added, “We took a gam­ble early on and im­me­di­ately de­vel­oped a large sup­ply of the hu­man pro­tein, and started us­ing that on the an­i­mals right away.”

Me­geney said the next step is to de­velop the first clin­i­cal tri­als of us­ing CT-1 in hu­man pa­tients – some­thing he hopes to see hap­pen­ing within three years.

“Typ­i­cally, the dis­cov­ery-to­trial is a min­i­mum of six to 10 years be­fore some­thing reaches the pa­tient pop­u­la­tion,” he said. “But with the way we con­ducted the ex­per­i­ments by us­ing the hu­man pro­tein, and the fact that (right heart fail­ure pa­tients) have no other op­tions, we’re look­ing at start­ing clin­i­cal tri­als in three years.”

Me­geney took his un­der­grad­u­ate stud­ies at St. Fran­cis Xavier Uni­ver­sity and started work­ing on his PhD at Dal­housie, fin­ish­ing study at the Uni­ver­sity of Water­loo.

He then went on to do ex­ten­sive post doc­tor­ate train­ing in molec­u­lar bi­ol­ogy at McMaster Uni­ver­sity.

He and his fam­ily reg­u­larly visit Pic­tou County.

SUB­MIT­TED

Dr. Lynn Me­geney, a se­nior sci­en­tist at the Ot­tawa Hospi­tal Re­search In­sti­tute, and pro­fes­sor in the De­part­ment of Medicine, at the Uni­ver­sity of Ot­tawa.

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