Silent Aortic Regurgitation in Hypertension

Abstract

Introduction Aortic Regurgitation (AR) is a common finding in echocardiograms. Although some early reports suggested hypertension (HTN) as a predisposing factor to aortic root enlargement and AR, such an association has not been shown in recent pathological and echocardiographic studies. In fact, the incidence and the clinical importance of silent or sub-clinical AR in hypertensive populations is unknown. The present case-control study was undertaken to explore the relations of HTN with trivial (1 +) to mild (2 +) AR. Subjects & Methods One thousand echocardiograms with Doppler records of 1000 inpatients 50 years or older were reviewed for presence of 1 + or 2 + AR. Patients with a history of aortic valve operation/prosthesis, history of rheumatic heart disease or rheumatic fever, or documented aortic valve disease were excluded. Twenty-two patients had moderate (3 +) to severe (4 +) AR and were excluded as well. A total of 140 patients found to have 1 + to 2 + AR became our study group (AR +). A control group of 140 individuals was selected randomly from the population with no AR (AR-). Patients in both study and control groups were screened for the presence of a history of HTN, duration of anti-hypertensive therapy and the systolic and diastolic blood pressure at the time of hospital admission. HTN + was defined as a history of HTN and on medical treatment. HTN- was defined as lack of the history or medical treatment. Admission HTN was diagnosed based on a blood pressure of 140/90 mmHg or more. Patients were divided into four sub-groups, as follows: AR + and HTN + (94 patients), AR + and HTN- (46 patients), AR- and HTN + (78 patients), and AR- and HTN- (62 patients). Other variables such as sex, age, mean arterial pressure, pulse pressure and aortic root dimension were defined and documented for all patients in both groups as well. Statistical testing was applied to discover the association of occurrence of AR with duration of anti-hypertensive therapy (as an indicator of duration of HTN) as well as other variables such as sex, age, admission systolic & diastolic pressures, aortic root dimension, mean arterial pressure, and pulse pressure. Results The multivariate logistic regression analysis identified the presence of HTN as being significantly associated with increased odds for the occurrence of AR. Analysis also demonstrated an association between increased aortic root dimension and AR. Furthermore, these odds were increased for each additional year of duration of treatment and each additional cm measurement of aortic root dimension in the definitive multivariate model. Conclusion: The result of our study suggests that the presence of HTN increases the odds of silent aortic regurgitation. Aortic root widening showed a similar correlation. The clinical implication and consequences of this silent aortic regurgitation in hypertensive populations is unknown. Further, it is uncertain whether successful treatment could decrease or slow down the occurrence of AR. Interestingly, chronicity rather than severity of hypertension is found to be a predictor in the occurrence of AR.