That said, there is evidence that the other coronaviruses that caused epidemics (SARS and MERS) can cause clinically meaningful myocarditis and heart failure as a result. In vitro and autopsy evidence suggests that SARS-CoV-2 directly infects myocardial cells. So it's plausible that there will be some cardiac sequelae of COVID, perhaps in many patients or maybe just in those at high risk. We just don't know. Assuming that myocarditis will be a major problem because 2 uncontrolled studies said so is as silly as assuming hydroxychloroquine works because of similar strength of evidence. But dismissing it out of hand (which I'm not suggesting GP is doing) is not smart either. We should be appropriately skeptical, but need to investigate further.