I think that what the author means is that there are twice as many heart surgeries perfomed here. Maybe that is because our cardiac wards are full of Canadians who come here for treatment.
And maybe it's not. One of the problems with discussing health care in Canada is that each province does it's own thing and consequently general criticisms are misleading. In Ontario several different hospitals , usually affiliated with a University specialize. If I had kidney problem ,I think it is University Hospital in London , if I had a heart problem I'd go here,
http://www.ottawaheart.ca/hcwhatisuohi.htm