Optimal blood pressure for patients with end‐stage renal disease following coronary interventions

Abstract Hypertension is a frequent manifestation of chronic kidney disease but the ideal blood pressure (BP) target in patients with coronary artery disease (CAD) with end‐stage renal disease (ESRD) (eGFR < 15 ml/min/1.73m2) still unclear. The authors aimed to investigate the ideal achieved BP in ESRD patients with CAD after coronary intervention. Five hundred and seventy‐five ESRD patients who had undergone percutaneous coronary interventions (PCIs) were enrolled and their clinical outcomes were analyzed according to the category of systolic BP (SBP) and diastolic BP (DBP) achieved. The clinical outcomes included major cardiovascular events (MACE) and MACE plus hospitalization for congestive heart failure (total cardiovascular (CV) event).The mean systolic BP was 135.0 ± 24.7 mm Hg and the mean diastolic BP was 70.7 ± 13.1 mm Hg. Systolic BP 140–149 mm Hg and diastolic BP 80–89 mm Hg had the lowest MACE (11.0%; 13.2%) and total CV event (23.3%; 21.1%). Patients with systolic BP < 120 mm Hg had a higher risk of MACE (HR: 2.01; 95% CI: 1.17–3.46, p = .008) than those with systolic BP 140–149 mm Hg. Patients with systolic BP ≥ 160 mm Hg (HR: 1.84; 95% CI, 3.27–1.04, p = .04) and diastolic blood BP ≥ 90 mm Hg (HR: 2.19; 95% CI: 1.15–4.16, p = .02) had a higher risk of total CV event rate when compared to those with systolic BP 140–149 mm Hg and diastolic BP 80–89 mm Hg. A J‐shaped association between systolic (140–149 mm Hg) and diastolic (80–89 mm Hg) BP and decreased cardiovascular events for CAD was found in patients with ESRD after undergoing PCI in non‐Western population.


INTRODUCTION
High blood pressure (BP) is an important risk factor for cardiovascular disease, and BP is significantly related to the risk of mortality and morbidity. 1 In the general population, BP values are correlated with cardiovascular (CV) risk starting from 115/75 mm Hg, and each 2 mm Hg reduction of DBP carries a 5% MI and 10% CV death risk reduction, indicating the importance of BP reduction for risk reduction. 2 Interestingly, the benefit of maintaining a lower BP target is not always observed in all patients. Adequate diastolic BP is crucial for coronary perfusion, and a lower BP target is not consistently beneficial for all coronary artery disease (CAD) patients, suggesting that BP targets should be considered individually for CVD. Our previous study reported that systolic BP < 120 mm Hg and ≥ 160 mm Hg or diastolic BP < 70 mm Hg was associated with a higher risk of CV events in CAD patients after coronary intervention, 3 providing the optimal BP target for CAD patients after percutaneous coronary intervention (PCI) in the Asian population. Among these CAD patients, those with poor renal function were especially important and attracted our attention. Renal failure or end-stage renal disease (ESRD) is a special disease entity among chronic kidney disease (CKD)s, and recommended treatment targets for the general population usually fail in this high-risk group.
For example, statins are suggested to reduce cardiovascular disease (CVD) mortality for CAD patients, including patients with CKD. However, the beneficial effect of statins was not observed in patients with ESRD or patients who underwent dialysis. 4 The complex interactions between factors such as malnutrition, inflammation, oxidative stress, vascular calcification, and rapidly progressing atherosclerosis may be responsible for the lack of effect of statins in patients with advanced renal failure, suggesting that the ESRD group is a special group of interest and that more clinical evidence is needed to provide better care for this high-risk group.
Additionally, maintaining adequate renal perfusion is believed to play an important role in caring for patients with simultaneously combined CKD and CAD. Although most clinical trials did not enroll patients with poor renal function, current guidelines still suggest that patients with CKD should be considered a high-risk group and that aggressive BP control is recommended to reduce future risk. [5][6][7] Figure 1A).
Regarding the CHF hospitalization incidence, there was a linear association between SBP values and the incidence of hospitalization for heart failure.
The same phenomenon appears in different age groups (age < 70 years and ≥ 70 years). In both groups, diastolic BP found similar U-shape result was found in MACE and total CV event. For those > 70 years, U-shape was still found in total CV event, but not so significant for the MACE (Table S2).

DISCUSSION
In the present investigation, we provide novel insights into the inter- Renal failure or ESRD is a special subgroup of CKD. Blood pressure before and after dialysis was especially susceptible to changes in fluid volume and electrolyte change in the body. Volume overload and sodium excess were the major mechanisms of high BP in dialysis patients. 10 Other pathogenic mechanisms, including sympathetic nervous system activation, the renin-angiotensin-aldosterone system, 13 arterial stiffness, 14 and endothelial dysfunction, 15 5 Although the optimal BP target is undetermined in patients with ESRD, poorly controlled BP is considered linked to worse clinical outcomes and associated with high all-cause and cause-specific mortality among dialysis patients. 17,18 Several studies showed the J-or U- with cardiovascular mortality after reviewing 9333 chronic hemodialysis patients in France. 17 All of the above studies suggested that the optimal BP target with the lowest future risk was different from the target in patient with CKD or the general population.
In our current study, we first clearly demonstrated the optimal BP maintained in ESRD patients combined with advanced CAD. All patients have received successful coronary intervention for their CAD.
To our interest, there have also been many debates about optimal BP maintenance in patients with CAD. In an international cohort study conducted by Vidal-Petiot and coworkers, it appears that systolic BP less than 120 mm Hg and diastolic BP less than 70 mm Hg increased cardiovascular risk, including cardiovascular death, myocardial infarction, or stroke, in patients with stable CAD. 22  For the relationship between heart failure incidence and BP values, no J-curve association was observed. A larger-scale population-based study is needed to confirm our observations.

CONFLICT OF INTEREST
The Author(s) declare(s) that there is no conflict of interest.

AUTHOR CONTRIBUTIONS
A consortium has been organized to conduct this study. All the investigators approved the paper.