You are reviewing a 65-year-old farmer in the post-PCI clinic. He had primary angioplasty to his RCA for an inferior STEMI 3 months previously. He reports exertional breathlessness but no chest pain. His current medications are aspirin 75 mg od, clopidogrel 75 mg od, ramipril 5 mg bd, bisoprolol 5 mg od, and atorvastatin 80 mg od. On examination his BP is 110/70 mmHg and his heart rate is 60 bpm. You hear a soft pan-systolic murmur at his apex. His chest is clear and there is no pedal oedema. His ECG shows atrial fibrillation. He manages only 3 minutes on the treadmill with no chest pain or ECG changes, stopping due to breathlessness. You request an urgent echocardiogram, which demonstrates mild LV systolic dysfunction. The inferior wall is akinetic, there is some tethering of the posterior mitral valve leaflet, and as a result some mitral regurgitation (ERO = 0.2 cm2 ).
What is the next appropriate step in his management?a. Start dabigatran
This patient has secondary MR. His recent infarct has led to alteration of his LV geometry (inferior akinesis) resulting in tethering of structurally normal MV leaflets. Ischaemic MR is a dynamic condition and its severity may vary depending upon changes in loading conditions. The ESC Guidelines published in 2012 propose that, because of their prognostic value, lower thresholds of severity using quantitative methods should be used in secondary MR. An ERO ≥20 mm2 or a regurgitant volume ≥30 mL/beat suggests severe MR. As ischaemic MR is a dynamic condition, stress testing may play a role in its evaluation. An exercise-induced increase in the ERO of ≥13 mm2 has been shown to be associated with a large increase in the relative risk of death and hospitalization for cardiac decompensation (ESC Guidelines 2012).