According to a survey from China, 10%-25% of cases of COVID-19 infection had underlying CAD. It is associated with an extremely high mortality rate in CAD patients. In a hospital-wide observational study in the United Kingdom, hospital admissions for ACS have gone down by 40% (compared with 2019) from January to April 2020, and were partially recovered in May. Similarly, the rate of PCI declined by 21% in patients with ST elevation myocardial infarction (STEMI) partly because of fear of contracting COVID-19 infection in the hospital along with loss of healthcare benefits. Pain perception is also altered due to COVID–related neurologic involvement.
COVID-19 can create an inflammatory milieu, which can trigger thrombotic events such as ACS. Myocardial injury due to COVID-19 infection can manifest in myriad of clinical presentations. Plaque rupture, microembolism, and vasospasm are underlying mechanisms of COVID–induced myocardial injury. These abnormalities occur due to shear forces in the coronary circulation leading to vessel injury. Type 2 MI due to metabolic derangements and hypoxia can also present as ACS. Microvascular dysfunction due to cellular injury can also present with angina symptoms (Figure 2-1).
Mechanism of myocardial infarction in COVID-19 infection. ACS, acute coronary syndrome.
Symptoms of MI in COVID-19 infection includes anginal chest pain and SOB along with typical features of viral pneumonia. Occasionally, ACS presentation is masked by respiratory symptoms; therefore, careful monitoring is required for timely diagnosis. Atypical presentations include syncope, dizziness, nausea, and fatigue.
ACS includes STEMI, non-ST elevation MI (NSTEMI), and unstable angina. MI can be classified into two types as per the fourth universal definition of MI:
The majority of MI cases in COVID-19 are attributed to demand and supply mismatch and a few are related to plaque rupture.
Although clinical history is the cornerstone of diagnosis, some patients can have overlapping symptoms between COVID-19 sepsis and ACS. Elevated troponin also can be seen in other COVID–related thromboembolic disorders.
The following criteria can be used for the diagnosis of MI in COVID-19:
Clinical features of MI
Elevated cardiac markers (troponin)
ECG changes consistent with ischemia (ST elevation, new Q waves, new left bundle branch block [LBBB])
Imaging findings consistent new loss of viable myocardium
Due to the current pandemic, all patients presenting with ACS should be tested for COVID-19 and the isolation protocol should be followed. Hospitals should follow a comprehensive protocol regarding the management of ACSs in patients with COVID-19. All patients should wear a mask and all staff should wear personal protective equipment (PPE). (1-6)
Approach to STEMI: Early diagnosis and intervention are the key regardless of COVID-19. All patients with STEMI should be treated with standard aspirin, P2Y12 inhibitor, and anticoagulation.
Prehospital care: In case of STEMI, EMS should alert the nearest PCI centers. Clinical information, ECG, and detailed COVID-19 exposure history should be provided. In case of NTSEMI, COVID-19 nasopharyngeal swabs should be sent before admission to the cardiology unit.
Hospital care: STEMI with COVID-19 infection should be transferred to the catheterization laboratory with standard PPE, surgical mask, gown, and gloves. Vital signs, oxygen saturation, and nasopharyngeal swabs should be promptly conducted. After angiography, the patient should be transferred to the COVID unit and the Cath Lab should be terminally cleaned. Air exchange timings in the Cath Lab should be maintained at 15 exchanges per hour.
In case of STEMI with cardiac arrest, intubation and resuscitation should be performed with full precautions along with powered air-purifying respirator before angiography is performed.
Thrombolytics can be administered alternatively based on hospital protocol if PCI is not available. Risk of COVID–associated thromboembolism and disseminated intravascular coagulation should be considered before fibrinolytics. Factors such as patient’s comorbidities, hemodynamic stability, age, severity of the disease, patients’ prognosis, and hospital resource limitation should also be considered.
PCI should also be considered over coronary artery bypass graft (CABG) in COVID-19 patients. Patients should be referred to COVID-free surgery centers after complete evaluation by nasal swabs and computed tomography (CT) scans (Figure 2-2).
Approach to NSTEMI and unstable angina: Patients with high-risk NSTEMI should undergo immediate invasive revascularization. On the other hand, patients with low- to intermediate-risk NSTEMI and unstable angina can be treated conservatively with aspirin, P2Y12 inhibitor, and anticoagulation. PCI is reserved for patients who remain unstable or have ongoing evidence of myocardial ischemia. All patients with NSTEMI and COVID-19 infection should be treated in the COVID unit with telemetry support.
Management algorithm of ACS in COVID-19 infection. NSTEMI, non-ST elevation myocardial infarction; PCI, percutaneous coronary intervention; STEMI, ST elevation myocardial infarction.
Complications of MI in COVID-19
Due to the delayed presentation of MI in the COVID-19 era, mechanical complications have been reported in the literature post MI. Free wall rupture, ventricular septal defect, and left ventricular aneurysms have been observed in post-MI patients with COIVID-19. Inotropic support and bedside placement of intra-aortic balloon pump (IABP) can be considered as a bridge to definitive surgical treatment.
ACS in COVID-19 patients has been associated with worse prognosis along with higher morbidity and mortality. Patients should be monitored post discharge with frequent telehealth visits and medication optimization. Risk factor modifications should be advised to avoid future events.