You might think that patients with painless MIs might have a better prognosis than patients with pain. Unfortunately, this is just not true. A recent study (1) supported prior literature indicating that the lack of pain is not a predictor of a more benign course, and in fact patients with painless MIs have a higher in-hospital and 1-year mortality. There are several other factors that may associate lack of pain with worse outcomes (e.g. painless MIs occur more often in older patients), but regardless it's important to remember that (1) many patients with MI will present without pain, and (2) the lack of "typical" symptoms should not be reassuring.
References
Cho JY, et a. Comparison of outcomes of patients with painless versus painful ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention. Am J Cardiol 2012;109:337-343.
