The Syst-Eur trial investigated whether active treatment starting with the dihydropyridine calcium channel blocker (CCB) nitrendipine, could reduce the cardiovascular complications of isolated systolic hypertension (ISH) in the elderly. The intention-to-treat analysis showed that active treatment improved outcome. The per-protocol analysis largely confirmed these results. The effect of treatment on total and cardiovascular mortality might be attenuated in very old patients. Further analysis also suggested benefit in those patients who remained on nitrendipine monotherapy. Active treatment was more beneficial in patients with diabetes as compared with those without diabetes at entry and reduced the incidence of dementia by 50%. Analyses of data from the Ambulatory Blood Pressure Monitoring (ABPM) Side Project suggested that most of the benefit of treatment was seen in patients with a daytime systolic BP > or = 160 mm Hg. Finally, a meta-analysis partly based on Syst-Eur data showed that in older hypertensive patients pulse pressure and not mean pressure is the major determinant of cardiovascular risk.