Case description
A 65-year-old woman with a
history of hypertension, diabetes, and chronic kidney disease secondary
to polycystic renal disease was the subject of a cadaveric-donor kidney
transplantation. Pre-transplant electrocardiogram and echocardiogram
were reported as normal. Immunosuppressive therapy was initiated with
tacrolimus and (besides a short period of time when it was suspended due
to medication related tremors) was administered uninterruptedly for five
years without novelty. During this time, tacrolimus plasma levels
remained within a range of 5.1-11.2 ng/mL (medium of 6.39 ng/mL).
In her fifth year of treatment, the patient developed lipothymia as well
as dyspnea with physical activity, asthenia and adynamia. Due to her
symptoms, a new echocardiogram was performed, which revealed findings
compatible with obstructive hypertrophic cardiomyopathy:
interventricular septum thickness of 15 mm and a left ventricular
posterior wall thickness of 11 mm (Figure 1) coupled with left
ventricular outflow tract obstruction signs (Figure 2 and 3) confirmed
by an end -systolic gradient (64 mmHg) in continuous Doppler through the
left ventricular outflow tract. No significant variants were detected in
the panel testing for genes ACTC1 (sarcomere gene), FLNC, LAMP2, MYL2
(sarcomere gene), PRKAG2 (related with glycogen storage disease), TNNI3
(sarcomere gene), TTR, CSRP3, GLA (related with Fabry disease), MYBPC3
(sarcomere gene), MYL3, PTPN11, TNNT2 (sarcomere gene), DES, JPH2, MYH7
(sarcomere gene), PLN, TNNC1, TPM1 (sarcomere gene) which are related
with genetic Hypertrophic Cardiomyopathy.
Initially considering surgical myectomy and cardiac resynchronization
therapy as measures to improve patient’s quality of life, a coronary
arteriography was performed with findings of moderate coronary artery
disease which was treated with stents placed in her right coronary and
circumflex arteries. Nevertheless, patient’s symptoms worsened, and
echocardiographic findings progressed. A review of the medical
literature arose consideration of the possibility that tacrolimus use
was the cause of our patient’s obstructive cardiomyopathy and medication
was discontinued. After switching immunosuppression therapy to an mTOR
inhibitor (sirolimus), symptoms resolved after about 1 year, and
echocardiographic findings reversed progressively after 2 years.