If in the future a patient comes to my clinic with complains of chest pain and show me his/her Apple Watch, I'd still use my own ECG, sphygmomanometer, 2D Echo with Doppler and order a complete metabolic panel including markers for MI (Troponin I, Creatine Kinase, etc). But if the Apple Watch would be the reason for patients to be more scrupulous about their health and be more compliant about their prescription meds then so be it. I'm just surprised that Apple still hasn't figured out how to add bioelectrical impedance to the Apple Watch since relying on the BMI isn't really a good metric.
My concern would be patients trying to self-diagnose themselves using the Apple Watch and I want to see the study on why the FDA approved the Apple Watch's ECG. Let's not forget the fact that an ECG isn't the only one used to evaluate heart health.