HCM and the renal function
Several previous studies examined the association between HCM and the
incidence of CKD including end stage renal disease (ESRD). From the
Korean nationwide population-based cohort study8, the
presence of HCM was associated with approximately a 7-fold increased
risk of newly diagnosed ESRD. Huang et al.9 reported
that approximately 15% of the HCM patients complicated with CKD whose
eGFR was <60 mL/min/1.73 m2 and HCM patients
with CKD had an increased risk of all-cause mortality. In the present
study, the prevalence of an eGFR<60 mL/min/1.73
m2 at baseline in the two groups was 56-67%, which
was higher than that in the above previous report9. In
HCM patients, the renal dysfunction may be attributed to impaired LV
diastolic dysfunction caused by LV hypertrophy and stiffness, which are
pathological features of HCM. A reduced LV diastolic function and
cardiac output leads to an increased LV filling pressure and renal
venous pressure, which eventually attenuates the renal function. As
there are few solutions for preventing the progression of LV diastolic
dysfunction in patients with HCM, the risk of developing CKD in this
patient population is a crucial problem. AF is the most common
arrhythmia in patients with HCM,3,15 in whom the
incidence is reported to be 20% in their lifetime2.
The loss of the atrial kick and irregular beats due to AF reduce the
stroke volume and cardiac output16. Several studies
have indicated the influence of CKD on the increased risk of
AF,17,18 and its mechanism is assumed to be persistent
inflammation related to CKD19 and mechanical stress
caused by a high atrial pressure due to hypertension and/or heart
failure associated with CKD20. The high prevalence of
CKD in the HCM patients of the present study indicated that the
coexistence of AF accelerates the deterioration in the renal function in
patients with HCM, and therefore, maintenance of sinus rhythm in
patients with HCM is highly desired.