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.