Unstable angina in the era of high-sensitivity troponin testing: a genuine entity and a cautionary tale.

High-sensitivity cardiac troponin assays have emerged as a powerful tool in the management of patients presenting acutely to hospital with suspected cardiac chest pain. Recent guidelines emphasize the reassurance offered by low troponin concentrations early after admission. We describe a patient with known coronary artery disease, who presented with a classical history of recurrent myocardial ischaemia. High-sensitivity cardiac Troponin-I concentrations remained in the low-normal sex-specific reference range, despite serial testing on the day of admission, and despite recurrent pain with dynamic ECG changes. Urgent coronary angiography confirmed severe multi-vessel disease. He required an intra-aortic balloon pump within 24 h due to clinical instability, and had urgent coronary artery bypass surgery a few days later. This case confirms that "unstable angina" remains a genuine entity. It highlights the hazards of over-reliance on any single test and serves as a reminder of the importance of integrating tests with clinical assessment.