A Nephrology-Focused Clinical Review: From Phenomapping to FINEARTS-HF
The Paulus-Tschope paradigm established that comorbidities—obesity, diabetes, CKD, hypertension—drive HFpEF through coronary microvascular endothelial inflammation rather than ischemia-mediated cardiomyocyte death. This inflammatory cascade begins when elevated IL-6, TNF-alpha, and CRP provoke endothelial dysfunction, reducing nitric oxide bioavailability, ultimately causing titin hypophosphorylation and increased cardiomyocyte stiffness.
Perhaps the most therapeutically actionable pathway linking CKD to HFpEF. MRs expressed in cardiomyocytes, fibroblasts, vascular endothelium, and immune cells stimulate TGF-beta, IL-6, and PAI-1, promoting fibrosis in both organs simultaneously. Critically, obesity and hyperglycemia cause ligand-independent MR activation even without elevated aldosterone.
Central mediator of bidirectional cardiorenal injury. Reduced eGFR correlates strongly with increased galectin-3 (r = −0.71, p = 0.01). Kidney injury upregulates galectin-3, which then initiates cardiac inflammatory and fibrotic processes.
Reduced GFR decreases sodium filtration capacity while RAAS activation prevents compensatory reductions in tubular reabsorption. Elevated central venous pressure from HFpEF reduces the arteriovenous pressure gradient across the kidney, creating “renal tamponade” that further decreases GFR.
ARIC Study (10,975 participants, 8.3 years): Continuous graded relationship between UACR and HF incidence, extending even within the “normal” range:
| UACR Category | HR for Incident HF |
|---|---|
| Optimal (<5 mg/g) | Reference |
| Intermediate-normal (5–9 mg/g) | HR 1.54 |
| High-normal (10–29 mg/g) | HR 1.91 |
| Microalbuminuria (30–299 mg/g) | HR 2.49 |
| Macroalbuminuria (≥300 mg/g) | HR 3.47 |
HOPE study: Every 0.4 mg/mmol UACR increase raises HF hospitalization risk by 11%. TOPCAT: 50% albuminuria reduction decreased HF hospitalization by approximately 30–70%.
The 2016 Circulation study by Shah et al. analyzed 397 HFpEF patients using 67 continuous phenotypic variables, identifying three distinct phenogroups through unbiased hierarchical clustering.
Phenogroup 3—the “CKD-vascular aging” phenotype—demonstrated HR 4.2 (95% CI 2.0–9.1, p<0.001) for HF hospitalization. Characterized by older age (median 75), CKD as the defining feature, 43% AF prevalence, pulmonary hypertension, and RV dysfunction.
The TOPCAT phenogroup analysis identified a similar cluster with the best response to spironolactone (NNT 14). CKD-associated HFpEF represents both the highest-risk phenotype and the subgroup most likely to benefit from targeted therapy.
Formally defined by Ndumele et al. (October 2023 AHA Presidential Advisory) as “a systemic disorder characterized by pathophysiological interactions among metabolic risk factors, CKD, and the cardiovascular system.”
| Stage | Definition | Key Actions |
|---|---|---|
| 0 | No CKM risk factors | Prevention |
| 1 | Excess/dysfunctional adiposity | Screen with eGFR + UACR even here |
| 2 | Metabolic risk factors or moderate-high CKD | SGLT2i for CKD, HF, or T2D (eGFR ≥20) |
| 3 | Subclinical CVD or risk equivalent; KDIGO G4/G5 (eGFR <30) = automatic Stage 3 | Intensive prevention; add finerenone for DKD with UACR >300 on ACEi/ARB |
| 4a/4b | Established CVD ± kidney failure | Full cardiorenal GDMT |
KDIGO Stage G4/G5 CKD (eGFR <30) is now treated as a cardiovascular risk equivalent under the CKM framework, warranting intensive prevention even without overt CVD.
5,988 patients, LVEF >40%: empagliflozin HR 0.79 (95% CI 0.69–0.90; p<0.001), NNT 30 over 26.2 months. Consistent benefit regardless of diabetes status.
6,263 patients, LVEF >40%: dapagliflozin HR 0.82 (95% CI 0.73–0.92; p<0.001). Benefit maintained even with LVEF ≥60%.
Consistent benefit across all prespecified subgroups including LVEF ≥60%. The 2023 ESC Focused Update upgraded SGLT2i to Class I, Level A for HFmrEF and HFpEF.
6,001 patients, LVEF ≥40%, across 634 sites in 37 countries: primary composite rate ratio 0.84 (95% CI 0.74–0.95; p=0.007) — 16% relative risk reduction. Remarkably consistent across the EF spectrum (p for interaction = 0.75).
K+ >5.5 mmol/L: 14.3% finerenone vs. 6.9% placebo (2.6-fold increase). By eGFR: eGFR ≥60 (0.3% vs 0.1% hospitalization), eGFR 45–<60 (0.4% vs 0.3%), eGFR <45 (1.2% vs 0.4%). No deaths attributable to hyperkalemia.
Phase II trial (NEJM 2025): simultaneous finerenone + empagliflozin achieved 52% UACR reduction — 29% greater than finerenone alone and 32% greater than empagliflozin alone. SAEs similar across groups (~6–7%).
Hyperkalemia with finerenone was substantially lower in SGLT2i users: 8.1% vs. 18.7% without SGLT2i. This suggests SGLT2i may mitigate finerenone-associated hyperkalemia through natriuretic and kaliuretic effects.
| eGFR | Starting Dose | Target |
|---|---|---|
| ≥60 | 20 mg daily | 20–40 mg |
| 25–<60 | 10 mg daily | 20 mg |
| <25 | Not recommended for initiation | |
Monitor K+ and eGFR at 4 weeks post-initiation. Uptitrate if K+ ≤4.8 and eGFR stable. If K+ >5.5: hold until ≤5.0, then restart at lower dose.
ADA 2024: Screen for asymptomatic HF in diabetics using BNP or NT-proBNP. In CKD (eGFR <60), higher thresholds of 200–400 pg/mL may be appropriate.