Renal resistive index and long-term outcome in patients with coronary artery disease

Renal arterial resistance index before and after vericiguat administration: Should it be considered the fantastic five?

BACKGROUND

Heart failure (HF) is a chronic-progressive disease. Once established, it is almost impossible to obtain a restitutio ad integrum of the cardiac function, but current strategies aim at slowing down the progression towards the terminal stages of the disease, which inevitably lead to the exitus. On the basis of these considerations, it appears clear that pharmacological interventions applied in this clinical condition should prevent first the development of the disease, by controlling the risk factors for HF thus reducing the onset of the disease, second slowing the disease evolution towards the terminal phases thus containing clinical symptoms and reducing the number of hospitalizations. In this scenario, the add-on therapy with vericiguat seems promising as reported in the VICTORIA study without affecting renal function. Several evidence indicates that renal arterial resistance index (RRI) seems to better reflect cardiovascular damage also in HF patients, thus affecting patients prognosis METHODS: In the present study we have analyzed the effect of vericiguat administration in 27 HF patients specifically evaluating RRI.

RESULTS

Vericiguat signicantly reduces RRI.

CONCLUSIONS

The findings of the present study seems to indicate that vericiguat, beyond its primary mechanism of action, might offer an additional advantage in HF patients.

The Relationship between Renal Resistive Index and Complexity of Coronary Lesions in Patients with Stable Coronary Artery Diseases

Background

The most common cause of coronary artery diseases (CAD) is atherosclerosis. The synergy between percutaneous coronary intervention with TAXUS™ and cardiac surgery (SYNTAX) score was used to assess complex CAD lesions. The renal resistive index (RRI) is a Doppler ultrasound parameter calculated to assess renal haemodynamics. The direct relationship between CAD complexity and RRI was not yet investigated. The aim of our study was to investigate this relationship between RRI and SYNTAX score in stable CAD patients.

Methods

This study included 214 patients with stable CAD and subsequent coronary angiography done at our institution. Regarding CAD complexity, these patients were classified into 166 patients with low SYNTAX score (SYNTAX ≤ 22), and 48 patients with high SYNTAX score (SYNTAX > 22). The demographic, laboratory, clinical, echocardiographic data and renal Doppler parameters; including RRI, were recorded.

Results

Multivariate logistic regression analysis demonstrated that RRI (odds ratio, OR = 4.440, 95% (confidence interval) CI: 1.418-13.903, p = 0.010) was a novel independent predictor of high SYNTAX score in patients with stable CAD, in addition to other traditional predictors as diabetes mellitus (OR = 4.401, 95% CI: 1.081-17.923, p = 0.04), low-density lipoprotein cholesterol (LDL-C) (OR = 2.957, 95% CI: 1.920-8.995, p = 0.027), multi-vessel CAD (OR = 2.113, 95% CI: 1.241-2.280, p = 0.001) and Gensini score (OR = 6.539, 95% CI: 1.977-21.626, p = 0.002). Receiver operator characteristic curve analysis showed that RRI > 0.655 (sensitivity of 80%, specificity of 73.6%) was the best cut-off value for predicting high SYNTAX score.

Conclusions

The non-invasively measured RRI is closely associated with high SYNTAX score in stable CAD patients.

Peripheral Artery Disease Ultrasound Assessment in Predicting the Severity of Coronary Artery Disease

Atherosclerosis in a progressive disease that is systemic in nature, and hence the simultaneous presentation of coronary artery disease (CAD) and peripheral artery disease (PAD) is not uncommon. As clinically manifested PAD is associated with worse cardiovascular outcomes, the timely identification of subclinical atherosclerosis seems of utmost importance. Ultrasonography (US) is an ideal imaging modality for assessing PAD that is easy to use, accurate, widely available and avoids unnecessary exposure to radiation. Several US parameters have been proposed in the assessment of PAD, with varying prognostic usefulness, depending on disease location. The aim of this review is to summarize the most important evidence available on the association between US-detected atherosclerosis in different vascular sites and the presence and severity of CAD, as well as the impact of the early detection of PAD on the outcomes of patients presenting with CAD.

Association of Preoperative Renal-Resistive Index With Long-term Renal and Cardiovascular Outcomes After Cardiac Surgery

OBJECTIVE

To investigate the association of elevated preoperative renal-resistive index (RRI) with persistent renal dysfunction, major adverse kidney events (MAKE), and major adverse cardiovascular events (MACE) after cardiac surgery.

DESIGN

Observational cohort study.

SETTING

University hospital.

PARTICIPANTS

Ninety-six adult patients undergoing cardiac surgery.

INTERVENTIONS

RRI measurement the day before surgery.

MEASUREMENTS AND MAIN RESULTS

Fifty-eight patients (60%) had elevated RRI ≥0.70. Five years after surgery, persistent renal dysfunction (sustained decline in estimated glomerular filtration rate ≥25%) had occurred in 25 patients (26%), MAKE (persistent renal dysfunction, renal replacement therapy, or death) in 34 (35%), and MACE (myocardial infarction, unstable angina, decompensated heart failure, stroke, or cardiovascular death) in 28 (29%). RRI was higher in patients who developed persistent renal dysfunction (median, 0.78 [IQR, 0.74-0.82] v 0.70 [0.66-0.77], p = 0.001), MAKE (0.77 [0.72-0.81] v 0.68 [0.65-0.76], p = 0.002), and MACE (0.77 [0.72-0.81] v 0.70 [0.66-0.77], p = 0.006). Patients with elevated RRI had a significantly higher cumulative incidence of all long-term outcomes. After adjustment for baseline renal function and heart failure, elevated RRI was associated with persistent renal dysfunction (hazard ratio [HR], 5.82 [95% CI, 1.71-19.9]), MAKE (HR, 4.21 [1.59-11.1]), and MACE (HR, 2.81 [1.03-7.65]).

CONCLUSIONS

Elevated preoperative RRI is associated with persistent renal dysfunction, MAKE, and MACE after cardiac surgery. Preoperative RRI may be used for long-term risk assessment in patients undergoing cardiac surgery.

Current Insights into the Significance of the Renal Resistive Index in Kidney and Cardiovascular Disease

Initially, the renal resistive index (RRI) was investigated with the aim of improving diagnosis in kidney diseases, but this goal was not met. Recently, many papers have highlighted the prognostic significance of the RRI in chronic kidney disease: specifically, in estimating the revascularization success of renal artery stenoses or the evolution of the graft and the recipients in renal transplantation. Moreover, the RRI has become significant in the prediction of acute kidney injury in critically ill patients. Studies in renal pathology have revealed correlations of this index with parameters of systemic circulation. The theoretical and experimental premises of this connection were then reconsidered, and studies analyzing the link between RRI and arterial stiffness, central and peripheral pressure, and left ventricular flow were conducted with this purpose. Many data currently indicate that RRI is influenced more by pulse pressure and vascular compliance than by renal vascular resistance-assuming that RRI reflects the complex interplay between systemic circulation and renal microcirculation and should be considered a marker of systemic cardiovascular risk beyond its prognostic relevance for kidney disease. In this review, we overview the clinical research that reveals the implications of RRI in renal and cardiovascular disease.

Maternal microvascular dysfunction during preeclamptic pregnancy

Preeclampsia is a hypertensive disorder of pregnancy effecting ∼5-8% of pregnancies in the United States, and ∼8 million pregnancies worldwide. Preeclampsia is clinically diagnosed after the 20th week of gestation and is characterized by new onset hypertension accompanied by proteinuria and/or thrombocytopenia, renal insufficiency, impaired liver function, pulmonary edema, or cerebral or visual symptoms. This broad definition emphasizes the heterogeneity of the clinical presentation of preeclampsia, but also underscores the role of the microvascular beds, specifically the renal, cerebral, and hepatic circulations, in the pathophysiology of the disease. While the diagnostic criteria for preeclampsia relies on the development of de novo hypertension and accompanying clinical symptoms after 20-week gestation, it is likely that subclinical dysfunction of the maternal microvascular beds occurs in parallel and may even precede the development of overt cardiovascular symptoms in these women. However, little is known about the physiology of the non-reproductive maternal microvascular beds during preeclampsia, and the mechanism(s) mediating microvascular dysfunction during preeclamptic pregnancy are largely unexplored in humans despite their integral role in the pathophysiology of the disease. Therefore, the purpose of this review is to provide a summary of the existing literature on maternal microvascular dysfunction during preeclamptic pregnancy by reviewing the functional evidence in humans, highlighting potential mechanisms, and providing recommendations for future work in this area.