Increase in elderly patients undergoing cardiac surgery. A worldwide phenomenon.

We read with great interest the article by Saito et al. w1x, and we absolutely agree with their findings; in particular, the importance of using a local risk stratification system for preoperative assessment of cardiac surgical patients. In Argentina, as well as in other countries, the ageing population is indeed an issue for several reasons. For instance, as physicians we face an increasing number of elderly patients suffering from preoperative comorbidities, a situation especially common among those undergoing cardiac surgery w2x. In this regard, it is worth mentioning that our risk model initially had 2.69% of the study population 80 years old or more. However, 10 years later the same age group represented 5.24% of the whole sample size (P-0.001). As stated by Saito et al. w1x, the number of comorbidities increased in our validating population w2x. We strongly agree with the development of epidemiological studies in different parts of the world, such as the one published by Saito et al., since they provide good insight into the local population characteristics and risks models, clearly different from those found in Latin America w2x, Asia w1x, Europe w3x or North America w4x. The first Latin-American risk stratification system for cardiac surgery: can be used as a graphic pocket-card score.