Type of publication:
*Pastfield E.; *Botley S.; *Pakala V.; *Ingram T.; *Lee E.
Journal of Cardiovascular Computed Tomography; 2020; vol. 14 (no. 1)
Introduction: Degenerative aortic stenosis is a common condition. Many elderly frail patients with multiple comorbidities now have an alternative to conventional surgery since the availability of transcutaneous aortic valve implantation (TAVI). Echocardiography (echo) remains the key tool for the diagnosis of aortic stenosis. CT calcium scoring, has proven a useful adjunct to diagnosis, when there are discordant echo measurements. The current societies' consensus propose a cut-off score (>2000 for men and >1200 for women) above which 'severe aortic stenosis is likely'. However, many elderly patients have discordant echo measurements, low calcium score despite having severe aortic stenosis. We propose that the adverse event rates in elderly patients, regardless of calcium score category, are not significantly different. Method(s): We retrospectively examined the records of consecutive patients undergoing CT calcium score between Jan 2017 and Sep 2019. These investigations were done, either for TAVI procedure planning or as an adjunct to assessing the severity of aortic stenosis (in the case of discordant echo measurements). All these patients were followed up for adverse events, defined as a composite of heart failure, chest pain or death. Statistical analysis was performed using SPSS 25 (IBM). Result(s): 88 patients, age 82+/-6 years, 55% men, underwent CT aortic valve calcium scoring and echo. Peak aortic velocity 3.9 +/- 0.8 m/s, mean gradient 35 +/- 13 mmHg, aortic valve area 0.8 +/- 0.2cm2, stroke volume index (SVI) 38 +/- 11 ml/m2. 52.4% of the study population had discordant echo measurements and 43.6% had SVI<35ml/m2. The calcium score for women and men were 2230 +/- 1250 and 3866 +/- 1997 respectively. 24% of these patients had calcium score below the cut-off value for 'likely severe aortic stenosis'. Median follow up was 382 days (range 66-1381 days) from the initial echo. Adverse events occurred in 20+/-4% and 29+/-5% in the 'high' and 'low' calcium score groups, independent t-test, p=0.40. Using Kaplan-Meier survival curve, there is no difference in the event free survival days between the two groups, 888 days for the 'low' and 702 days for the 'high' calcium score groups, Log rank Chi-square=0.26, p=0.61. Conclusion(s): In an elderly population with aortic stenosis, there is no difference in short term adverse event rates (composite of heart failure/death/chest pain) as categorised by their calcium scores. Therefore, the current diagnostic approach may under estimate the severity of aortic stenosis in some patients. [Formula presented]