Patients Characteristics
Based on the exclusion criteria, 20 patients were excluded from this
study (2 cases of ascending aortic replacement and/or aortic
valvuloplasty, 2 cases of moderate or severe AS, 16 cases of IE). In
total, 126 patients were eligible for this study (mean age 67 ± 12
years, male 73%). Table 1 shows their baseline clinical
characteristics, comorbidities and echocardiographic measurements. Three
fourths of the study subjects were hypertensive, and 43% of them had
chronic kidney disease (CKD) (estimated glomerular filtration rate
< 60 ml/min/1.73m2). Thirteen (10%)
patients had a connective tissue disease (rheumatic arthritis 5,
systemic lupus erythematosus 2, Marfan syndrome 1, Takayasu arteritis 1,
autosomal dominant polycystic kidney disease 2, polymyalgia rheumatica
1, Behçet’s disease 1). More than half of them had severe AR, resulting
in their dilated left ventricular (LV) size (LV end-diastolic diameter:
60 mm) with slightly reduced LV ejection fraction (51%) as well as
slightly dilated sinus of Valsalva (38 mm) (median values,
respectively).
Etiologies of AR (Table 2)
In all the study subjects, the most common etiology of AR was cusp
bending (33.0%), followed by aortic root enlargement (22.2%), and
bicuspid AV (17.4%). Seven (5.5%) patients had both AV cusp bending
and aortic root enlargement. Even normal finding was also noted in 7.9%
of the subjects. In AV cusp bending, right coronary cusp (RCC) was the
most affected (90.5%, 38 out of 42 cusp bending cases).
Comparison between Cusp Bending and Non-Cusp Bending Groups(Table 3)
As the next step, all the study subjects were classified into 2 groups
with or without aortic cusp bending on any cusp. The number of patients
with cusp bending was 49 (mean age 72 ± 7 years), whereas that of those
without cusp bending was 77 (mean age 64 ± 14 years). The age was
significantly higher in the cusp bending group (p = 0.0017). While the
patients with aortic cusp bending had significantly lower height (159 vs
165 cm, median, p = 0.0037) and less body surface area (1.58 versus 1.63
m2, median, p = 0.0287), LV echo measurements did not
differ between the 2 groups. However, those with cusp bending had
smaller diameters of Valsalva sinus (36 vs 39 mm, median, p = 0.0188),
ST junction (30 vs 33 mm, median, p = 0.0150) and mid-ascending aorta
(35 vs 38 mm, median, p = 0.0097). In addition, patients with mitral
prolapse were observed only in the cusp-bending group (8% vs 0%, p =
0.0053).
AR Etiologies According to Age (Table 4)
Subsequently, all the subjects were re-classified into 2 groups based on
their age at 65 years: the elderly group (n = 85, mean age 74 ± 5 years)
and the younger group (n = 41, mean age 52 ± 11 years). In the elderly
group, cusp bending was the most frequent cause of AR (48.2%), and RCC
was the most affected cusp (90.2%). On the other hand, in the younger
group, bicuspid AV was the most common etiology (36.5%), and cusp
bending accounted for only 19.5% in this group.
To examine the contributing factors to aortic cusp bending, logistic
regression analysis was performed with age, hypertension, diabetes, CKD
and connective tissue diseases included as dependent variables, which
revealed that age was the only factor associated with cusp bending
(Table 5).