http://www.ergo-log.com/sculptors.html
The researchers think that the sculptors were protected by the physical nature of their profession. Sculpting is hard work. According to modern studies, a sculptor weighing 65 kg burns 6.5 to 9.1 calories a minute. A painter weighing the same gets no further than 2.3 to 3.9 calories per minute. By the way, both professions expend more calories than someone who earns a living sitting at a computer.
It's possible that the physical work protected the sculptors against cardiovascular disease. That is what many classic studies from the twentieth century concluded about physical work, in the period before doctors started to prescribe statins.