Monday, December 07, 2009


Angioplasty is now it her 32rd year ( Sept 15th, 1977 ). Through all the years, we have always battled with the problem of re-stenosis, the achilles heel of angioplasty. Back in 1993 before the publication of the STRESS and BENESTENT ( these are the two large scale clinical trial that established the role of the stent ) results, we all were sure that the stent would solve the problem of restenosis. Well, it did to a certain degree. We reduced restenosis ( plain old balloon angioplasty restenosis of 40-50 % ) from 40-50% to 15-20% with the bare-metal stents ( in particular the JnJ PS 153 ). That was not good enough and we were soon developing drug-coated stents. The RAVEL results were know at the turn of the century, in 2001, which showed that with the CYPHER ( JnJ Cordis, sirolimus eluting stent ), at one year, in a highly selective population, the restenosis was zero %. I thought that that was two good to be true. Sure enough when one studied the restenosis with the DES in an allcomers population, the DES restenosis rate is probably nearer 5-10%. The there is the problem with stent thrombosis. But that is another story for another day.
So after 32years, we have improved from a restenosis rate of 40-50% to 5-10%. To be honest, during the 32years, we have also moved the goal post. The initial POBA ( plain old balloon angioplasty ) restenosis rates were all angiographically determined ( meaning we tend to see more with the angiogram, and so tend to do more ). Nowadays, unless it is for clinical trial purposes, more and more studies are prepared to use clinical re-stenosis rates and target lesion re-vascularisation or target vessel failures. Be that as it may;
I wanted to share an important clinical study with you that comes from Norway. Dr Peter Munk and colleagues from Stavanger University Hospital, Norway, that appeared in the American Heart Journal Nov 2009. They studied the effects of intensive exercise on restenosis. They studied 80 patients, 40 in the control arm, on the usual regular follow-up following PCI with DES or BMS, and 40 patients on an intensive exercise program following PCI with DES or BMS. Intensive exercise program, included a supervised exercise program for 60 mins, with 10 mins warm up and 10 mins recovery. They exercise for 40 mins either on the bicycle ergometer, or the treadmill, achieveing a target heart rate about 80-90% maximum. This exercise is followed three times a week, and at the end of six months, the patients were re-studied. They found that the late lumen loss was 0.39mm for those in the contrlled arm and 0.10mm for those in the intensive exercise arm. There was also improvement in their Hs-CRP levels and peak oxygen uptake and flow mediated dilatation. Basically, everything was better especially the arterial lumen.
True, this is a small study but I like the study because, it does mean that patients can help to take care of themselves. Sometimes, we have patients who feel that once that have survived and paid for the procedure, everything is done, and they are OK. They then revert to their old habits, hoping that tehy will be well, and should they get restenosis, they would blame the procedure and maybe the operator for doing a bad job.
Besides that, the study also generates a few hypothesis. For example, it would appear that inflammation plays an important role in late lumen loss. And that this inflammation is not well controlled by the drug on the stent. Anyway, some of the patients in the study had bare-metal stents and so there is no drug to talk of, and yet they had benefited from intensive exercise.
Of course, it would appear that the senior citizens who may not be able to exercise, are at a disadvantage.
Whatever it is, all those of you out there who have a stent put in, you can help yourselves if you keep fit with exercise for one hour three times a week. It may help to reduce your chance of stent restenosis, and save you time, risk and money.

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