Comparison of central blood pressure and cardio-ankle vascular index for association with cardiac function in treated hypertensive patients

Abstract

Recent automated applanation tonometry can measure radial pulse wave-derived central blood pressure (CBP), which has shown a prognostic value independently of peripheral blood pressure. However, CBP's clinical significance has not been fully established. We examined the associations between CBP and cardiac structure and function by comparing them with those of arterial stiffness assessed by cardio-ankle vascular index (CAVI) in treated hypertensive patients. Enrolled in the study were 102 patients (71 ± 7 years) with treated hypertension. The transmitral early-to-atrial velocity ratio (E/A), peak systolic (S¢), early diastolic (E¢) mitral annular velocities and the Tei index were measured as indexes of cardiac function derived from conventional and tissue Doppler echocardiography. Left ventricular mass index (LVMI) was measured as an index of LV hypertrophy. CBP and CAVI were measured just after echocardiographic examination. CBP, but not CAVI, correlated with LVMI (r¼0.306, Po0.01). Although CBP correlated only with the Tei index (r¼0.201, Po0.05), CAVI correlated with E/A (r¼À0.387, Po0.001), S¢ (r¼À0.270, Po0.01), E¢ (r¼À0.362, Po0.01) and the Tei index (r¼0.339, Po0.01). Stepwise regression analysis revealed that neither CBP nor CAVI was independently associated with E/A, S¢ or E¢. However, CAVI, but not CBP, was independently associated with the Tei index (b coefficient¼0.311, Po0.001), reflecting both LV systolic and diastolic function. In conclusion, CBP may be suitable for detecting LV hypertrophy. In contrast, CAVI may be suitable for detecting LV dysfunction. This difference, suggesting the clinical value of each parameter, should be kept in mind when we use CBP and CAVI for assessing arteriosclerosis in treated hypertension.

Head-to-head comparison of the cardio-ankle vascular index between patients with acute coronary syndrome and stable angina pectoris

“…18,19 Furthermore, CAVI was not associated with the peak creatine kinase level in ACS patients. These results may suggest that CAVI would not be directly affected by the myocardial infarct size.…”

“…15,16 LV diastolic dysfunction is associated with an increased CAVI. 7,[17][18][19] Thus, the ACS patients, who would have an abrupt and severe myocardial ischemia, could have a higher CAVI than SAP patients. (2) Systemic acute inflammation and an elevated level of interleukin-18 are strongly associated with increased arterial stiffness.…”

Central blood pressure, arterial stiffness and the heart in hypertensive patients

“…8 PWV was significantly associated with LVMI in women but not in men. The higher prevalence of men (62%) in the study by Masugata et al 1 Although the authors did not discuss it much, the interaction between the heart and the arterial system, ventricular-arterial coupling, can be a key determinant of cardiovascular performance. Thus, the pathophysiological and clinical implications of arterial stiffness should be considered in conjunction with cardiac function.…”

“…Elevated aortic SBP combined with a relative reduction in coronary perfusion during diastole could promote LV concentric remodeling and hypertrophy. Although arterial stiffness is one of the underlying mechanisms of increased central SBP, Masugata et al 1 found that CAVI, an index of arterial stiffness, was not related to LVMI after correcting for other confounding parameters. As central BP is influenced by other factors related to wave reflections, such as sex, heart rate and body height, central BP and arterial stiffness require different indices.…”

“…10 One mechanism by which increased arterial stiffness may directly affect diastolic function and ventricular relaxation involves the effect of the early return of the reflected pressure wave, which augments the late-systolic pressure and causes a compensatory increase in ejection duration that in turn results in a delay in ventricular relaxation and a prolonging of the time constant of isovolumic relaxation. 11 The Tei index used in the study by Masugata et al 1 is the ratio of the sum of the isovolumic systolic and isovolumic diastolic time to ejection time. The correlation of CAVI to the Tei index may be explained in part by the above mechanism.…”