People who drink diet sodas have 44% more heart attacks and strokes than those who don't. Pretty good sample size in this new study: N = 2564, 36% men, mean age 69 ± 10, 20% white, 23% black, 53% Hispanic. Done in Manhattan. They controlled for all the other stuff that (we know) influences CV events (age, sex, race/ethnicity, education, smoking, physical activity, alcohol consumption, BMI, daily calories, consumption of protein, carbohydrates, total fat, saturated fat, and sodium).

SOURCES
http://www.springerlink.com/content/b042807u865853t7/
http://www.medscape.com/viewarticle/758833?src=mpnews&spon=34