Critical Care Cardiology

Section Co-leads:

• Aniket Rali, MD (@aniket_rali)
• Venugopal B. Bhattad, MD
• Sarah Rosanel, MD (@DrRosanel)

Section Contributors:

• Narayana Sarma V. Singam, MD (@singamnv)

Incidence

• The incidence of CS in COVID-19 patients is not reported in the literature and is limited only to several case studies.
•  Several studies indicate that patients with acute myocardial injury, heart failure, and myocarditis are at risk for CS (Tavazzi et al, European Journal of Heart Failure, 2020; Zeng et al, Infection, 2020; Hu et al. n.d, European Heart Journal, 2020.).

Pathophysiology

• Acute myocardial dysfunction from COVID-19 is the likely driver for CS. Both nonischemic and ischemic cardiomyopathies have been noted with SARS CoV-2 and can induce shock.
• Myocarditis leading to CS has now been established in two case studies and has an incidence of approximately 5% (Hu et al. n.d., European Heart Journal, 2020; Zeng et al. Infection, 2020; Ma et al. n.d., MedRxiv, 2020.).
• Acute myocardial injury from direct viral toxicity to myocardium was noted in one case study (Tavazzi et al. European Journal of Heart failure, 2020).  
• Although acute ischemic cardiomyopathies such as atherothrombotic myocardial infarctions can trigger CS, there has not been any literature demonstrating this mechanism in COVID-19 patients.

Diagnosis (Vahdatpour, Collins, and Goldberg, Circulation, 2019)

• There is no consensus for the definition of CS. However, the AHA review for CS provides some generic guidance based on previous CS studies
• Systolic blood pressure < 90mmHg for 30 minutes or with use of vasopressors
• End organ damage
• Oliguria/anuria
• Altered Mental status
• Elevated lactic acid > 2 mmol/L
• Cardiac Index < 2.2 and PCWP > 15 mmHg
• Transthoracic echocardiography is helpful in evaluating LV structure and function, RV structure and function, wall motion abnormalities, and valvopathies
• Serum biomarkers of troponin above the 99^th percentile indicates acute myocardial injury (DeFilippis et al. Circulation, 2019).
• Electrocardiography and coronary angiography are also useful diagnostic tools to identify etiology of CS
• One study utilized endomyocardial biopsy (EMB) to demonstrate viral particles within the myocardium and potentiating direct viral toxicity to the heart. EMB maybe useful to delineate the underlying disease pathology (Tavazzi et al., European Journal of Heart Failure, 2020).

Management

• Management of CS with respect to COVID-19 is multifactorial. Literature specific to COVID-19 is sparse. General pharmacotherapy to treat CS include:
• Diuretics
• Inotropes/vasopressors
• Vasoactive agents
• Invasive hemodynamic monitoring can be considered
• Use of mechanical support in COVID-19 related CS has been noted in several case reports and a recent review article (Chow et al., CJC Open, 2-2020).
• VA ECMO may have a role in therapy
• IABP has also been used to manage CS in these patients (Tavazzi et al., European Journal of Heart Failure, 2020).
• Therapy of underlying etiology (e.g., fulminant myocarditis)
• In patients with myocarditis, high dose steroids and immunoglobulins were administered in addition to standard therapy for CS (Hu et al. n.d., European Heart Journal, 2020.).

Prognosis

• The prognosis of CS and COVID-19 is not well described. All three studies with COVID-19 related CS demonstrate that patients had recovery of myocardium. However, in two studies patients still died of subsequent septic shock (Zeng et al., Infection, 2020.; Tavazzi et al., European Journal of Heart Failure, 2020; Hu et al. n.d., European Heart Journal, 2020.). 

Case 1: Chest pain and ST elevation.  Ref (Fried et al, circ., 2020)

• 64 year-old woman (HTN, HLD) with chest pain, +Covid19
• ECG -  sinus tach, STE in leads I, II, aVL, V2-V6, PR elevation & ST depressions in aVR.
• Troponin 7.9 ng/mL – peaked at 18.6 ng/mL
• Cardiac catheterization: nonobstructive coronary artery disease 
• Complicated by drop in BP to 70/40s. Right heart catheterization: RA pressure: 10 mmHg, PA pressure:  30/20 mmHg, PCW pressure: 21 mmHg and a Fick CI of 1.0 L/min/m – Cardiogenic shock
• Insertion of intraaortic balloon pump (IABP) + dobutamine infusion
• TTE: EF 30% initially improved to 50% on hospital day 10

• Background
• Extracorporeal method of cardiorespiratory support in patients with failing heart and lungs
• Helps sustain perfusion and gas exchange
• Experience of ECMO use in COVID 19 is limited (Yang et al., Lancet Respiratory Medicine, 2020)
• Appropriate candidate selection is necessary for best outcome (2)
• COVID-19 can precipitate leukopenia that can be further exacerbated with ECMO and caution is necessary prior to initiation of this mechanical support device (Henry et al., Lancet Respiratory Medicine, 2020).
• Resource limitations also further necessitate careful candidate selection
• Candidate Selection (Ramanathan et al., Lancet Respiratory Medicine, 2020)
• VV-ECMO (Veno-venous ECMO) should be considered for primary respiratory failure alone
• VA-ECMO (Veno-arterial ECMO) should be considered for cardiovascular involvement (i.e., cardiomyopathy and cardiogenic shock)
• Exact indications and timing are not well elucidated 
• Additional Considerations
• Limited ECMO resources, trained personnel, and infrastructure may limit access to patients during this pandemic (MacLaren el. al., JAMA, 2020).
• Guidelines/Expert Opinion
• American Thoracic Society suggests that ECMO be considered in failing prone ventilation. Case-by-case analysis is recommended (Wilson et al., ATS, 2020).
• Surviving Sepsis Campaign suggests considering ECMO in refractory hypoxemia despite optimimal ventilation, rescue therapies, and proning (weak recommendation due to low evidence) (Alhazzani et al., SCCM, 2020) 
• The Australian and New Zealand Society Intensive Care Society (ANZICS) COVID 19 guidelines does not recommend early use of VV ECMO but suggests discussions with ECMO specialists (AZNICS Collaborators, AZNIC, 2020)

This article is intended for educational purposes only. The CCC does not make any recommendations for or against any therapy.

Case Report from Italy (Tavazzi et al, Eur. J. Heart Fail., 2020) 

• 69‐year‐old patient with flu‐like symptoms for 4 days à respiratory distress, hypotension, and cardiogenic shock. 
• Treated with ECMO and mechanical ventilation. 
• Cardiac function fully recovered in 5 days and ECMO was removed. 
• Endomyocardial biopsy: low‐grade myocardial inflammation and viral particles in the myocardium suggesting either a viremic phase or infected macrophage migration from the lung.