From: mdkline@rodan.acs.syr.edu (Mark D. Kline)
Subject: Re: Mitral Valve Prolapse
Organization: Syracuse University, Syracuse, NY
Distribution: usa
Date: Mon, 20 Jul 92 18:10:40 EDT

In article <1628@hsdndev.UUCP> rind@binoc.bih.harvard.edu (David Rind) writes:
>In article <1992Jul19.223030.1409@newstand.syr.edu>
> mdkline@rodan.acs.syr.edu (Mark D. Kline) writes:
>>There are several convincing studies and reviews and the clinical experience
>>of both psychiatrists and cardiologists supports this widely recognized
>>association.  See for example Klein DF, Gorman J: J Clin Psychiatry
>>1985;2:14-17 (monograph).   
>
>To be convincing, I would expect a population based cohort study that
>identified patients with MVP independent of any symptoms, and followed
>them forward (without telling them they had MVP -- not unreasonable
>for the benign types of MVP) to look for the development of symptoms.
>Obviously the person evaluating for the development of anxiety would
>have to be blinded to the diagnosis as well.

Demanding criteria allright.

>
>I haven't seen any studies that even come close to this design.  If
>you know of one, I will happily go look it up.  I am unimpressed by
>the "clinical experience" of cardiologists and psychiatrists -- there
>is a large reason to expect referral bias.  This is like the ENT
>physician who told me he thought penicillin 250mg qid was inadequate
>for strep throat since he kept seeing patients who failed this therapy.
	[ stuff deleted ]

I don't think the referral bias problem is really the same in these
two clinical situations.   I value clinical experience, although
I recognize its limitations.


>>I stand by my point here; care to cite a study suggesting
>>increased mortality among people with MVP? 
>
>Sure -- Look at the New England Journal:  Marks AR et al. April 20,
>1989 1031-36.  Patients with MVP who had redundant mitral valve tissue
>had higher rates of endocarditis and need for mitral valve replacement.
>Given that both these conditions have a fairly high mortality, this
>suggests that this form of MVP is associated with higher mortality.

The article you cite supports my original point that MVP as an isolated
cardiac finding is benign.  They suggest that if the  i
mitral valve is prolapsed, and has thick leaflets redundant tissue, THEN
you are at higher risk of eventual complications.  Without these findings
MVP is benign.

I call your attention to the editorial appearing in the same issue
of that journal by Dr. Richard B Devereux of Cornell, entitled
"Diagnosis and Prognosis of Mitral Valve Prolapse", which states in part:

"...calculations suggest that 4000 sudden deaths per year may be
attributable to mitral valve prolapse.  Although these are relatively
large numbers in absolute terms, they represent a very small fraction
of the  almost seven million patients with MVP in this country..."

Devereux goes on to suggest that young, female patients without systolic
murmur in the absense of endocarditis are probably at "extremely low risk."
Devereaux also points out the limitations of the study you cite
(selective population, no systematic auscultation, and finally, 
uncertainty as to whether the thickened and enlarged valve leaflets 
preceed and predict complications or whether they are
"wear and tear" phenomena accompanying mitral valve regurgitation. 
(p. 1078)).

I hope this controversy is finally reasurring to the anxious people out
there who have uncomplicated mitral valve prolapse.

--
=================================================================
mark kline                                mdkline@mailbox.syr.edu
suny health science center, syracuse      voice: (315) 422-1050
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