At stage-1 study, we investigated the prevalence of treated-resistant hypertension. But, the mechanism of treated-resistant hypertension has not been clarified. Previous study showed that a total of 248 drug metabolism pathways with known CYP involvement. Of 57 putatively functional human CYPs only about a dozen enzymes, belonging to the CYP1, 2, and 3 families, are responsible for the biotransformation of most foreign substances including 70%-80% of all drugs in clinical use[8]. We hypothesized that the resistance results from the either epigenomical modifications of the gene encoding the enzymes related to drug metabolism and the gene encoding drug receptors or genomic variants for cardiovascular disease (GWAS studies provided).