Anginal pain and elevated troponin level despite normal coronary angiography: hypertrophic cardiomyopathy with severe obstruction due to vasodilator/diuretic therapy for coincident arterial hypertension

A 69-year-old female patient with dyspnea (NYHA III), chest pain (CCS II), and an elevated high-sensitivity troponin I (hs-TnI) level (274 ng/l in the face of normal creatinine – 78 µmol/l) was admitted to our department. She had a history of arterial hypertension (max. 190/140 mm Hg) and hypercholesterolemia. ECG revealed sinus rhythm of 75 beats per minute, ST-segment elevation in V2 up to 2 mm and a negative T wave in V2–V6. On current (three drugs) pharmacotherapy consisting of an angiotensin receptor blocker, a diuretic and a very low dose of metoprolol (25 mg/day), blood pressure was 112/61 mm Hg (the relatively low value for arterial hypertension was probably related to left ventricular outflow tract (LVOT) obstruction; see echocardiogram description below).
Echocardiography was performed prior to coronary angiography. Current angina pectoris, with elevated troponin level, ischemic signs in ECG and risk factors of coronary artery disease – age 69 years, smoking and hypertension – were arguments for the decision to perform coronary angiography (on the admission day, both echocardiography and coronary angiography were performed). Echocardiography revealed significantly reduced left ventricle (LV) cavity size with akinesia of the apex and the presence of thrombus (Figure 1 A). Asymmetric LV hypertrophy (LV end-diastolic septal thickness of 2.0 cm) and severe LVOT gradient of 85 mm Hg (Figure 1 B) with systolic anterior movement (SAM) of mitral leaflet in resting condition were detected as a common picture of hypertrophic cardiomyopathy (HCM) (Figure 1 C). Thick mitral valve leaflets are a frequent phenomenon in HCM as well as a early phenomenon of genotype positive but phenotype negative HCM patients. The coronary artery angiogram was normal in left side epicardial coronary vasculature, and nearly normal with insignificant stenosis of the right coronary artery.
The vasodilator and diuretic were gradually decreased (to maximize LV preload) and were substituted by increasing doses of -blocker. Simultaneously both LVOT gradient and hs-TnI level decreased in day-by-day monitoring to normal values (Figure 1 D, final levels: hs-TnI = 8.4 ng/l and LVOT gradient = 12 mm Hg). The time profile of the NT-proBNP level declined but the last measurement was still markedly above the normal value (admission – 5789 pg/ml, 3rd day – 2415 pg/ml, discharge – 541 pg/ml). Anginal pain and dyspnea gradually decreased. Finally, at discharge, the patient was in...


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