Impact of the augmentation time ratio on direct measurement of central aortic pressure in the presence of coronary artery disease

The augmentation index measured by using the central artery pressure is associated with an increased risk of coronary artery disease (CAD). However, no study has examined the role of the time duration of the central artery pressure on CAD. Therefore, we evaluated the relationship between the central blood pressure time duration and the presence of CAD. All patients without a history of revascularization or prior myocardial infarction who underwent an elective coronary angiography at one of the two hospitals from January to September 2013 were analyzed. CAD was defined as a significant stenosis in one of the main coronary branches. The augmentation time ratio was defined as the ratio of the reflection to peak systolic time T2T1 duration divided by the peak systolic time to aortic notch T3T2 duration. We analyzed the relationship between the central pressure waveform (not only augmentation pressure) and the presence of CAD. A total of 146 (57.3%) out of 255 patients had a significant CAD. T2T1 duration was longer in the CAD group than the no CAD group, and the T3T2 duration was shorter in the CAD group than the no CAD group. The augmentation time ratio (T2T1/T3T2) was significantly larger in the CAD group than in the no CAD group. The augmentation index and augmentation pressure were lower in the no CAD group, but this difference was not statistically significant. The augmentation time ratio was an independent factor related to no CAD, especially in patients with a high augmentation index (odds ratio, 2.17; 95% confidence interval, 1.02-4.63). The augmentation time ratio was an independent factor related to the presence of CAD.