Author + information
- Zaher Fanari,
- Jhapat Thapa,
- Kamleish Persad,
- Sumaya Hammami,
- Michael Kostal,
- Erik Marshal,
- Joseph West and
- Andrew Doorey
Current guidelines discourage aortic stenosis (AS) evaluation by direct pressure measurement if echocardiography (echo) is adequate. Crossing the valve at catheterization (cath) is a class III recommendation due to potential stroke risk and the fact that echo derived AVA correlates highly with cath derived AVA. However several studies show sizable differences between echo and catheterization (cath) lab measurements. Using pressure wire for aortic stenosis assessment may offer a safe and higher quality techniques to assess the validity of echo results.
Sequential patients with suspected AS by echo (n=75) aged 61-94 underwent right and left heart cath by two operators with pressure gradients via left ventricular (St. Jude) pressure wire and ascending aorta catheter. Values were based on simultaneous pressure wire recording of left ventricular pressure and fluid filled pressure catheter recording of aortic pressure measured > 5 cm above the valve. Cardiac output was calculated by thermodilution. Echos were from 5 different labs, interpreted by 18 different readers, and reviewed by 2 independent level III readers blinded to original reads and cath results to assess the quality of community-based readings.
Independent readers considered 66 of the 75 echos to have good quality. There was no difference between these and poorer quality echos at predicting cath parameters.
Independent reader interpretation did not significantly differ from the original interpretation. 23 patients had an EF < 50%, 52 had an EF > 50%. Cath Assessment of severity of aortic valve area (AVA) was discordant with echo by more than 0.2cm2 in 48%, 0.3cm2 in 25% and 0.5cm2 in 7% of patients. Values changed to over or under the surgical threshold of AVA <1cm2 in 30% of the patients (Pearson correlation of 0.47). Mean echo gradients had better correlation with cath gradients (75%, Pearson correlation of 0.82). Urgent surgical valve replacement was avoided in 18 patients (24%). No clinical strokes or TIA were observed in the 30 days after procedure.
Cath-echo correlation of AS severity is lower in contemporaneous practice than previously assumed. This can alter the decision for aortic valve replacement. Sole reliance on echo-derived assessment of AS may need to be reconsidered.