ASSESSMENT OF DRUG EFFICACY USING HOME SELF-BLOOD PRESSURE MEASUREMENT - THE SMART STUDY

The SMART study (Self Measurement for the Assessment of the Response t o Trandolapril) was a large scale trial conducted by general practitio ners in order to assess the informative value of home self-measured bl ood pressure (BP) for the evaluation of therapeutic intervention. Afte r a 2-week wash-out period, patients with office diastolic blood press ure (DBP) between 95 and 120 mm Hg received trandolapril, 2 mg once da ily for 4 weeks. Four days of self-recorded BP were performed both at the end of the wash-out period and at the end of the treatment period with an automatic printer-equipped device using the oscillometric meth od (A&D UA 751). Every day, a series of three consecutive measurements was planned in the morning before drug intake and repeated in the eve ning. A total of 1710 patients (946 men, 764 women) aged 56 +/- 11 ent ered the study. In the 816 patients who correctly performed self-measu red blood pressure (SMBP) during both periods and followed the protoco l schedule, office BP (SBP/DBP) decreased from 166.4 +/- 15/101.4 +/- 6 mm Hg to 144.7 +/- 14/86.1 +/- 8 mmHg while SMBP decreased from 153 +/- 18/94 +/- 10 mm Hg to 139 +/- 16/85 +/- 10 mm Hg. A weak correlati on was found between the two methods with regard to systolic (r = 0.47 , P < 0.0001) and diastolic (r = 0.36, P < .0001) BP lowering. Individ ual response to therapy varied between the two methods: 633 patients ( 77.6%) exhibited at least a 10 mm Hg office DBP decrease while 493 (60 .4%) presented at least a 6 mm Hg self measured DBP decrease in the ev ening; 65% of patients were considered as responders with both methods . The 24-h therapeutic coverage was assessed by the morning to evening BP decrease ratio (M/E ratio) which represents the ratio of the troug h effect to the 12-h post dosing efficacy. Both population and individ ual M/E ratios ranged between 73% and 86% thus confirming the long dur ation of action of trandolapril. In conclusion: (1) discrepancies betw een office and self-measured BP evaluation of therapeutic response hav e been pointed out: agreement between the two methods is obtained in o nly 65% of patients, mainly due to intra-individual BP variability and recording conditions; and (2) self-measured BP could be a potential t ool to explore the 24-h therapeutic coverage.