Two preliminary studies offer mixed news for heart patients who fall ill with COVID-19: Those on certain blood pressure-lowering drugs are not at increased risk of dying, but those with atrial fibrillation (a-fib) may be. In one study, researchers reviewed records from nearly 400 COVID-19 patients who were hospitalized at their center between March and June 2020. The investigators found that those who suffered an a-fib episode during their stay had a substantially worse prognosis -- being more likely to develop heart or kidney complications, or to die.