Objective: The Plaque Hypertension Lipid Lowering Italian Study (PHYLLIS), is the first study in patients with hypertension (diastolic blood pressure (DBP) 95-115 mmHg; systolic blood pressure (SBP) 150-210 mmHg), moderate hypercholesterolaemia (LDL-cholesterol 4.14-5.17 mmol/l (160-200 mg/dl) and initial carotid artery alterations (maximum intima-media thickness (IMT) Tmax > or = 1.3 mm). The primary objective of PHYLLIS is investigating whether in these patients administration of an angiotensin converting enzyme inhibitor, fosinopril, and a statin, pravastatin, is more effective than administration of a diuretic and a lipid-lowering diet in retarding or regressing alterations in carotid IMT. While the study is in progress, baseline data are here reported to clarify the association of various risk factors with carotid IMT in these medium-high risk hypertensive patients.
Methods: Patients numbering 508 have been randomized to PHYLLIS by 13 peripheral units, in Italy. Age was (mean +/- SD) 58.4 +/- 6.7 years, males were 40.2%, current smokers 16.5%, means +/- SD of serum total, low-density lipoprotein (LDL), high-density lipoprotein (HDL) cholesterol and triglycerides concentrations were 6.79 +/- 0.67, 4.69 +/- 0.51, 1.37 +/- 0.38, 1.59 +/- 0.64 mmol/l (262.4 +/- 25.8, 181.3 +/- 19.8, 53.0 +/- 14.6, 141.0 +/- 56.7 mg/ dl). Means +/- SD of clinic sitting SBP/DBP were 159.8 +/- 9.0/98.3 +/- 4.2 mmHg. 483 of the 508 patients also had 24 h ambulatory BP monitoring, edited and read at a centralized unit (mean +/- SD 24 h SBP/DBP averages 136.3 +/- 14.1/84.0 +/- 10.0 mmHg). Quantitative B-mode ultrasound (Biosound 2000 II 5A, Biosound, Indianapolis, Indiana, USA) recordings of carotid arteries were taken by certified sonographers in the peripheral units and tracings were all read at a central unit. CBMmax (mean IMT of eight sites at common carotids and bifurcations) was 1.21 +/- 0.17; Mmax (mean of 12 sites also including internal carotids) 1.16 +/- 0.17, and Tmax (single maximum) 1.85 +/- 0.48 mm.
Results: Ambulatory SBP and pulse pressure (PP) (24 h, daytime, night-time averages) and their variability indices (24 h SD) were always significantly correlated with CBMmax and Mmax (P0.01 -0.001), and the correlations remained significant after adjustment for age, gender and smoking. No measurement of DBP was ever associated with any IMT measurement. Likewise, no lipid variable was found associated with any IMT measurement.
Conclusions: Baseline data from PHYLLIS indicate that in this population of hypertensive patients with moderate hypercholesterolaemia, SBP and PP are with age among the most significant factors associated with carotid artery alterations. However, the narrow range of inclusion LDL-cholesterol and DBP values may have obscured an additional role of these variables.