04 May

The Natural History and Rate of Progression of Aortic Stenosis: Stenosis Progression

The Natural History and Rate of Progression of Aortic Stenosis: Stenosis ProgressionA concern, identified in the studies cited above, is that a small proportion of asymptomatic patients may progress very rapidly to develop symptoms and then die suddenly. If, however, one could identify reliable predictors to the rate of progression of aortic stenosis, then surgical consideration may be given to these high-risk, yet asymptomatic patients. In addition, a common clinical scenario is that of a patient with documented aortic stenosis, not of a severity that would routinely result in a surgical intervention, in whom cardiac surgery is planned for other reasons. The question is whether the aortic valve should be replaced at the time of this surgery? Knowledge of reliable predictors to stenosis progression would greatly aid in clinical decision making.
Table 1 summarizes a review of the literature on the progression of aortic stenosis. Doppler echocardiography records the maximal difference between the instantaneous left ventricular and aortic pressures at any point during the systolic ejection period. Catheter-derived peak-to-peak gradient is a nonsi-multaneous measurement determined by the difference between the peak left ventricular and aortic systolic pressures. The Doppler-derived peak instantaneous gradient is thus always higher than the peak-to-peak gradient. The difference in these values decreases as the absolute gradient increases. The mean gradient, which is the average gradient throughout systole, should theoretically be equivalent, and studies have shown this to be true. canadian health&care mall

When cardiac catheterization is used as the tool of observation to follow the rate of progression of aortic stenosis, there will be inherent biases as to the patients selected for follow-up. Only patients who have progressed symptomatically would be subjected to the risk of a second cardiac catheterization. Doppler echocardiography is a noninvasive, reliable tool, ideally suited to follow up asymptomatic patients with aortic stenosis and thus allow a more accurate reflection of the natural progression.

Table 1—Rate of Progression of Aortic Stenosis: A Review

Source Year No. Method Follow-up,yr Initial AP, mm Hg t APper Year IAVA per Year Faster Rate of Increase
Wagner and Selzer 1982 50 Catheter 3.5 38 5.4f Older age, calcific valve
Nitta et al 1987 11 Catheter 3 23 7.7f Older age
Turina et al 1987 29 Catheter 7 50 3.4* None
Schuler et al 1991 11 Catheter 3.4 56 8.4f None
Davies et al 1991 65 Catheter 7 10 6.5f Calcific valve
Otto et al 1989 42 Doppler 1.7 54 12§ 0.1 Progressive symptoms
Roger et al 1990 112 Doppler 2.1 35 4.8§ Progressive symptoms
Faggiano et al 1992 45 Doppler 1.5 64 15* 0.1 Lower LV systolic function
Peter et al 1993 49 Doppler 2.6 38 7.2* Older age, coronary artery disease

Categories: Aortic Stenosis
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