Was the valve used in National Heart Centre operation approved as a medical device?

While the HSA was conducting their briefing about how they were going to tweak the regulatory processes for low risk devices, we have this bit of exciting news about the groundbreaking operation done at the National Heart Centre.

Exciting because it was the first such operation done in Asia. Essentially, the operation was a minimally invasive insertion of a bioprosthetic (cow tissue in steel) valve to correct for a mitral valve failure. The valve-in-valve design was developed in 2007 when it first underwent clinical studies. In November last year the Edwards SAPIEN valve received a much heralded approval from the FDA. But here is where there is a bit of problem. The FDA approval was only for the use of the valve for aortic valve stenosis, not for correction of the mitral valve. And only in patients who are too ill for open heart surgery. In fact the US FDA had made a note in its approval that the valvular operation, even for aortic stenosis was not without problem - patients had 3 times more chance of developing a stroke.  But there had been no similar FDA approval for a modified valve for mitral valvular disease. Gigamole is not sure if any major regulatory agencies have approved the mitral version of the valve, let alone the HSA.

So here are Gigamole's questions:

a] Did the FDA approve the mitral valve-in-valve as a medical device?
b] Did any regulatory agency world wide approve the mitral valve-in-valve medical device?
c] Did the HSA approve the mitral valve-in-valve medical device?  And if so, on what grounds? If not, what was the approval process for surgeons at the National Heart Centre to go ahead and operate using an FDA and HSA unapproved medical device?

Please do not mistake my questions as being anti-innovation and anti-progress. Devices such as this valve-in-valve device needs to be properly evaluated in terms of risk benefits before use. The aortic version was studied since 2007 before it was approved by the FDA. Although the valve had been modified for mitral valve use also in 2007, this never received the same warm response, and as far as Gigamole is aware, the FDA in its wisdom never gave approval for the mitral valve version. Treating the mitral valve is not as straightforward on terms of risk-benefit assessments as for aortic stenosis. To those who advocate that we blindly follow the FDA's approval must also accept that we should also take guidance from the FDA's tardiness in approving this procedure.

Defibrillators for resuscitations - all talk and no action

It would seem that gyms and sporting facilities, and also parks, are not regulated in anyway with respect to the provision of resuscitative equipment. It's pretty much NATO - no action all talk only. Everybody wants to run CPR training cos they get money for course attendances, but when it comes to actually installing the equipment, it's pretty much dependent on organizationsto want to play ball.

The Singapore Heart Foundation just recently published lists of all the organizations and places where automated external defibrillators are installed. A consolidated list of places can be found here. My gym isn't on the list. Neither is the East Coast Park. Nor is the Prince George's Park Residence gym.

So there.

Maybe I can encourage you to speak to your gym, or sports facilities and pressure them to install appropriate resuscitative equipment. Perhaps you can also write in to National Parks and persuade them to be a bit more civic conscious and install appropriate resuscitative equipment in adequate quantities and in readily accessible locations. Their email is: NPARKS_MAILBOX@NPARKS.GOV.SGThis e-mail address is being protected from spambots. You need JavaScript enabled to view it

Sudden death in the gym - adequate CPR support?

The recent fatal collapse of an NUS lecturer in the Prince George's Park Residences gym raised a number of concerns for me.

First of all is, whether there are adequate support for cardiopulmonary resuscitation to be done?

Although it was reported that CPR was started but was unsuccessful, I really question if proper CPR was at all possible. I can't imagine that there would be trained gym instructors at a hostel gym. Furthermore I really doubt if proper CPR equipment was available; don't even mention a defibrillator!

Which was a tragic shame....because in a young man with cardiac arrest, CPR/defibrillation could be life saving.

Which raised in my mind, a second question - how many gyms in Singapore are properly equipped for CPR? At the gym in the club I frequent, I discretely asked the instructor if there was any CPR equipment available. He stammered a bit and insisted there was. When I asked where, he stammered a bit more and said he didn't know.... perhaps it was out of order and sent for repairs. Then he said it was in the store room. Who had the key? That question really got him. I didn't want to embarass him further so I left it there. Bottom line was that even if there were CPR equipment it was not accessible in any way should an hapless auntie collapse from coronary insufficiency.

Then I thought a bit more..... what about at our parks? When I was at the East Coast Park the other weekend, I couldn't help marvelling at the thousands of weekend warriors who flock there every Sunday. If someone collapses, how does one do CPR? Does anyone know if there is a defibrillator anywhere? Why can't the park have well signposted CPR stations at regular intervals?

Hmmm....

I wonder who is responsbile for ensuring there is adequate support for public cardiopulmonary resuscitation in Singapore? Or is everyone wishing someone else would do it?

Seasons of the heart - sudden death

One of the more interesting reports in the newspapers recently, other than the usual stuff about human organ trade and the conflicts within regulatory agencies :), was the tragic report about the student who died suddenly. Raffles Institution student Tee Yan Chyuan, merely 12 years of age, had collapsed suddenly after a game of badminton and died. He had apparently been very fit before, and was said to have died from cardio-respiratory failure failure....which generally means no one knows why. I don't think the forensics report is out yet, at least not out in the public domain.

I have posted a bit about this before. In an adult, usually the more senior ones, the commonest cause of such sudden deaths are usually related to an fatal arrhythmia (cardiac seizure) due to coronary insufficiency. Although these patients are getting younger and younger, coronary insufficiency is unable to account for the cases who are very young, who die suddenly. Most certainly, this young boy would not have died of coronary insufficiency. Coincidentally, there is a current report in CNN about the same kind of problem but in patients treated with antipsychotic drugs.

Just Googling the problem turns up various reviews about this problem. A fairly representative review can be found here. It always amazes me that the heart can maintain such intricate rhythms without failing. Something of a miracle no matter how you look at it. Yet I believe sometimes it does seize up....but very very rarely. Sometimes it occurs in the context of coronary insufficiency, when the heart does not get enough oxygen. But in the very young it may inexplicably just seize up for no other reason than the delicate mechanisms driving the heart rhythms just screw up. Sometimes this may be the consequence of a rare (very rare) genetic abnormality of the various mechanisms (ion channels etc) regulating the flow of ions and electrical currents of the heart. This may often require some sort of environmental trigger, such as exercise or some medicine/chemical. There is a particular genetic abnormality of calcium handling that confers a high risk of a heart seizing up particularly during exercise. I don't think we will ever know what really happened to this boy. Such deaths leave no footprints, and I can imagine it will be very difficult for the forensic team to figure this out (CSI or no).

Understanding this, of course presents little comfort to the family of Tan Yan Chyuan. My heart goes out to them. It is a very tragic and painful loss. I can't imagine the pain of ever losing any of my own bao beis (precious ones).

Seasons of the heart - bradycardia, arrhythmias and sudden death

A younger colleague stopped me over the weekend and asked my opinion of an young otherwise healthy individual with a resting heart rate of 40/min. I had to admit to pausing for while before answering. The normal range for a normal heart rate is probably about 60-100/min. Quite often we do see individuals with heart rates between 50-60, especially if they are aerobically quite fit. But 40/min is a bit of a stretch below the normal range especially considering that the atrial and nodal pacemakers start to kick in. Marathon runners can drop their heart rates down to 40. But here the individual wasn't quite a marathon runner...merely borderline fitness. He had a heart rate of 40, no escape rhythms (ECG done), and otherwise cardiovascularly normal.

I passed him as normal.

But it made me think a bit more about the heart. Amazing organ. At an average heart rate of 72/min, with a lifespan of 80 years, the heart would have beaten over 3 billion times. Isn't that incredible? And all this while, the complex movement of Na+, K+ and Ca++, through intricately regulated ion channel activities, maintain appropriate heart rhythms that allow us to function normally through extreme ranges of physical activities. It's just such a miracle that we don't all seize up and die. When you think about it, we wouldn't really require a myocardial infarct to die of ventricular fibrillation. Yet most of us will live through this uncertainty.

Perhaps the sudden death cases that we read about in young people ...or crib deaths in infants....are nothing more than the random occurrences of electrical convulsions of the heart? Intrinsic risks of life. Food for thought.