Acute Papillary Muscle rupture in STEMI complicated by Cardiogenic shock during the Covid-19 era
Presenter
Mohit Pahuja, MD, MedStar Washington Hospital Center, Oklahoma City, OK
Mohit Pahuja, MD1, Ezequiel Molina2, Ron Waksman, M.D.2 and Itsik Ben-Dor, MD2, (1)MedStar Washington Hospital Center, Oklahoma City, OK, (2)MedStar Washington Hospital Center, Washington, DC
Title
Acute Papillary Muscle rupture in STEMI complicated by Cardiogenic shock during the Covid-19 era
Introduction
Papillary muscle rupture (PMR) in ST elevation myocardial infarction (STEMI) patient is a potentially lethal complication because of the acute severe mitral regurgitation (MR). Many of these patient presents with cardiogenic shock (CS) and often require mechanical circulatory support (MCS) devices for hemodynamic stability.
Clinical Case
73-year-old male with no reported history presented with chest pain for 24 hours. In the ED, he was hypotensive with BP of 73/50 mmHg. He was hypoxic and his oxygen saturation was 74%. His ECG showed ST-elevations in leads V4-V6. He was started on norepinephrine and immediately sent to the catheterization lab. His left-heart-catheterization showed that he had a 100% occluded-OM1, 80%-OM2 and 60%-LAD disease. His CS was out of proportion considering these findings. A left-ventriculogram was performed which demonstrated at least 3+MR with hyperdynamic LV. His right heart catheterization showed: RA: 10 mm Hg; RV: 45/10 mm Hg; PA: 66/22/38 mm Hg; PCWP: 29 mm Hg with v wave of 50 mm Hg; CO (Fick): 2.3 L/min; CI (Fick): 1.2 L/min; PA saturation: 33%. He was intubated and intra-aortic balloon pump (IABP) was placed. His catherization findings raised concern for PMR. An echocardiogram was performed which confirmed this suspicion and also demonstrated a normal LVEF. His HS-troponin was elevated at 68,915 and his lactic acid continued to worsen to 9 mmol/L despite IABP support. His COVID-19 test came back negative. He was taken to the operating room immediately given the progression of shock. He underwent mitral valve replacement, IABP explant and Impella 5.5 insertion for better hemodynamic support. Because of, poor coronary targets he was unable to undergo bypass. Over the next few days, the cardiogenic shock resolved and the improved Impella 5.5 was explanted. He was eventually discharged to rehab facility.
Discussion
Patients that developed PMR after STEMI often presents with CS and require MCS device for hemodynamic support. The use of IABP in STEMI is considered a class IIa indication according to ACC guidelines. IABP may decrease afterload and myocardial oxygen demand and improve coronary blood flow, but the effects on cardiac output are modest and often require more robust MCS devices. The use of other MCS devices such as Tandem Heart, Impella or ECMO in these patients has been reported. It can be challenging to use impella in these patients because of increased risk of damaging papillary muscles. The goals of the MCS device are to decrease afterload, improve forward blood flow and improve systemic blood pressure while decreasing left ventricular end-diastolic pressure and improving MR. Emergent cardiac catheterization and early revascularization can improve outcomes and decrease mortality in these patients. High degree of suspicion is required in patients with STEMI and CS to look for mechanical complications. Left ventriculography can be useful to investigate these complications. The timing of surgery for patients with PMR is often challenging due to the hemodynamic instability and worsening CS but early utilization of MCS devices can be helpful when performing emergent surgery.