Of the 22 576 patients who enrolled in INVEST, a total of 6166 (27.3%) had a history of previous coronary revascularization: CABG, 2784 (45.2%); PCI, 2594 (42.1%); and CABG+PCI, 788 (12.8%). The revascularized patients, compared with the nonrevascularized patients, were older, more frequently male, residents of the United States, and white, with a higher prevalence of characteristics associated with risk for adverse outcomes, including previous MI, CHF, stroke/transient ischemic attack, and peripheral vascular disease (P<0.001; ). As expected, the nonrevascularized patients more frequently had angina and left ventricular hypertrophy (P<0.001).
Patient Characteristics at Baseline, by Revascularization Status
BP and Treatment
At baseline, revascularized patients had lower BP than nonrevascularized patients (148.0/83.5 versus 151.9/ 88.5 mm Hg; P<0.001 for SBP and DBP; ) and more patients with BP in control (<140/90 mm Hg: 29.0% versus 20.2%, P<0.001; within Sixth Report of the Joint National Committee guidelines: 24.1% versus 16.9%, P<0.001). At 24 months, BP was decreased in both groups (adjusted for baseline BP: revascularized, −17.6/−10.9 versus nonrevascularized, −19.4/−9.8 mm Hg), with SBP somewhat higher and DBP somewhat lower among revascularized patients compared with nonrevascularized patients (132.9/75.7 versus 131.7/78.0 mm Hg; P<0.001 for SBP and DBP). As a consequence, pulse pressure decreased less for revascularized patients than for nonrevascularized patients (adjusted for baseline BP: −6.5 versus −9.6 mm Hg; P<0.001). For all of the patients, the greatest decrease in BP was seen during the first 6 weeks of treatment, followed by additional decreases during the subsequent 5 months, which were maintained through 24 months (). Fewer revascularized patients had adequately controlled BP (<140/90 mm Hg: 69.5% versus 71.9%, P<0.01; within Sixth Report of the Joint National Committee guidelines: 59.7% versus 63.8%, P<0.001). However, among revascularized patients, the verapamil SR- and atenolol-based treatment strategies resulted in similar control of BP (at 24 months: SBP 133.2 versus 132.6 mm Hg, P=0.29; DBP 75.8 versus 75.7 mm Hg, P=0.75). At 24 months, significant decreases in BP had occurred for all of the revascularized patients, regardless of technique of revascularization (CABG: −14.8/−7.4, PCI: −15.7/−8.2, CABG+PCI: −13.8/−7.3 mm Hg; P<0.0001 for SBP and DBP).
BP control for revascularized and nonrevascularized patients. The mean follow-up period was 32.9±10.3 months.
Primary and Secondary Outcomes
The revascularized patients had a proportionately higher incidence of primary and secondary outcomes than the nonrevascularized patients (), and the difference between the cumulative primary outcome rates increased over time (). The unadjusted risk for primary outcome was higher for revascularized patients compared with nonrevascularized patients (HR: 1.46; 95% CI: 1.34 to 1.59). However, after adjustment for baseline conditions, this increased risk diminished (HR: 1.15; 95% CI: 1.05 to 1.26), and with propensity score analysis it resolved (HR: 1.06; 95% CI: 0.93 to 1.22). In a fourth analysis that adjusted for baseline conditions and follow-up BP, the results were similar to the adjustment for baseline conditions only (HR: 1.17; 95% CI: 1.06 to 1.28). There was no significant change in these latter results when the 1154 “no-follow-up-BP” patients were excluded from analysis (HR: 1.15; 95% CI: 1.05 to 1.26).
Risk for clinical outcomes for revascularized and nonrevascularized patients.
Survival without primary outcome as a function of time and revascularization status.
Similar to the entire INVEST population, there was no difference in primary outcome for the revascularization patients based on treatment strategy (data not shown).11
The interaction between the ethnicity and revascularization on the risk for primary outcome was not significant (all P
The most frequent secondary outcome for all of the patients was death, followed by total MI (fatal and nonfatal; ). Revascularization during follow-up occurred in only 557 (2.5%) of all of the enrolled patients. However, it was 3.4 times more likely in the revascularized patients (5.1%, versus 1.5% for nonrevascularized patients; P
<0.0001). Both in patients with and without previous revascularization, there were no differences in the revascularization rates during follow-up based on treatment strategy (2.49% for verapamil SR- versus 2.43% for atenolol-based strategies; P
Relationships Between Primary Outcome and BP
Relationships between the incidence of primary outcome and mean follow-up SBP and DBP for the revascularized and nonrevascularized patients were quadratic, or J shaped. (). A J-shaped curve was also apparent for both patient groups, to a lesser degree for SBP and a greater degree for DBP, for the relationships between the adjusted HR for primary outcome and mean follow-up SBP and DBP. These relationships persisted after propensity score analysis (). The SBP/DBP nadirs were 135/70 and 125/75 mm Hg, respectively.
Figure 4 Incidence of primary outcome (bar graphs) and HR (line graphs; adjusted for baseline conditions, without propensity score analysis) as a function of SBP and DBP in patients with and without previous revascularization. Reference SBP and DBP for HR: 140 (more ...)
Comparison of HR (adjusted for baseline conditions) without and with propensity score analysis as a function of SBP and DBP in patients with and without previous revascularization. Reference SBP and DBP for HR: 140 and 90 mm Hg, respectively.