Cardionephrology from the point of view of the cardiologist: no more agree to disagree-getting to 'yes' for every patient

From cardiorenal syndrome to nephrocardiology: The journey of exploring the interconnection between nephrology and cardiovascular medicine

The knowledge about the pathophysiology of cardiorenal syndrome has evolved remarkably over the past two decades. However, cardiorenal syndrome is only one subject within a much broader field of nephrocardiology, which encompasses the interconnection between nephrology and cardiovascular medicine from nine different standpoints of pathophysiology, epidemiology, prevention, prognosis, diagnosis, therapy, monitoring, risk factors and systemic diseases. The complexities of these nine elements of the interaction between nephrology and cardiovascular medicine are not adequately addressed in either of those two fields of medicine. Nephrocardiology is an emerging field in medicine aiming at addressing those subtleties to improve prognosis and quality of life of a large and vulnerable patient population with combined cardiovascular and nephrology related conditions.

Cardiac Structure and Function and Subsequent Kidney Disease Progression in Adults With CKD: The Chronic Renal Insufficiency Cohort (CRIC) Study

RATIONALE & OBJECTIVE

Heart-kidney crosstalk is recognized as the cardiorenal syndrome. We examined the association of cardiac function and structure with the risk of kidney failure with replacement therapy (KFRT) in a chronic kidney disease (CKD) population.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

3,027 participants from the Chronic Renal Insufficiency Cohort Study.

EXPOSURE

Five preselected variables that assess different aspects of cardiac structure and function: left ventricular mass index (LVMI), LV volume, left atrial (LA) area, peak tricuspid regurgitation (TR) velocity, and left ventricular ejection fraction (EF) as assessed by echocardiography.

OUTCOME

Incident KFRT (primary outcome), and annual estimated glomerular filtration rate (eGFR) slope (secondary outcome).

ANALYTICAL APPROACH

Multivariable Cox models and mixed-effects models.

RESULTS

The mean age of the participants was 59±11 SD years, 54% were men, and mean eGFR was 43±17mL/min/1.73m2. Between 2003 and 2018 (median follow-up, 9.9 years), 883 participants developed KFRT. Higher LVMI, LV volume, LA area, peak TR velocity, and lower EF were each statistically significantly associated with an increased risk of KFRT, with corresponding HRs for the highest versus lowest quartiles (lowest vs highest for EF) of 1.70 (95% CI, 1.27-2.26), 1.50 (95% CI, 1.19-1.90), 1.43 (95% CI, 1.11-1.84), 1.45 (95% CI, 1.06-1.96), and 1.26 (95% CI, 1.03-1.56), respectively. For the secondary outcome, participants in the highest versus lowest quartiles (lowest vs highest for EF) had a statistically significantly faster eGFR decline, except for LA area (ΔeGFR slope per year, -0.57 [95% CI, -0.68 to-0.46] mL/min/1.73m2 for LVMI, -0.25 [95% CI, -0.35 to-0.15] mL/min/1.73m2 for LV volume, -0.01 [95% CI, -0.12 to-0.01] mL/min/1.73m2 for LA area, -0.42 [95% CI, -0.56 to-0.28] mL/min/1.73m2 for peak TR velocity, and -0.11 [95% CI, -0.20 to-0.01] mL/min/1.73m2 for EF, respectively).

LIMITATIONS

The possibility of residual confounding.

CONCLUSIONS

Multiple aspects of cardiac structure and function were statistically significantly associated with the risk of KFRT. These findings suggest that cardiac abnormalities and incidence of KFRT are potentially on the same causal pathway related to the interaction between hypertension, heart failure, and coronary artery diseases.

PLAIN-LANGUAGE SUMMARY

Heart disease and kidney disease are known to interact with each other. In this study, we examined whether cardiac abnormalities, as assessed by echocardiography, were linked to the subsequent progression of kidney disease among people living with chronic kidney disease (CKD). We found that people with abnormalities in heart structure and function had a greater risk of progression to advanced CKD that required kidney replacement therapy and had a faster rate of decline in kidney function. Our study indicates the potential role of abnormal heart structure and function in the progression of kidney disease among people living with CKD.

From cardiorenal syndromes to cardionephrology: a reflection by nephrologists on renocardiac syndromes

Cardiorenal syndromes (CRS) are broadly defined as disorders of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction of the other. CRS are currently classified into five categories, mostly based on disease-initiating events and their acuity or chronicity. CRS types 3 and 4 (also called renocardiac syndromes) refer to acute and chronic kidney dysfunction resulting in acute and chronic heart dysfunction, respectively. The notion of renocardiac syndromes has broadened interest in kidney-heart interactions but uncertainty remains in the nephrological community's understanding of the clinical diversity, pathophysiological mechanisms and optimal management approaches of these syndromes. This triple challenge that renocardiac syndromes (and likely other cardiorenal syndromes) pose to the nephrologist can only be faced through a specific and demanding training plan to enhance his/her cardiological scientific knowledge and through an appropriate clinical environment to develop his/her cardiological clinical skills. The first must be the objective of the subspecialty of cardionephrology (or nephrocardiology) and the second must be the result of collaboration with cardiologists (and other specialists) in cardiorenal care units. This review will first consider various aspects of the challenges that renocardiac syndromes pose to nephrologists and, then, will discuss those aspects of cardionephrology and cardiorenal units that can facilitate an effective response to the challenges.

Cardiovascular changes in young renal failure patients

Progresses in medical care of severe kidney disease and congenital anomalies of kidney and urinary tract make it possible for a higher percentage of young renal failure patients to survive and enter adulthood. There is thus an increasing need to focus on the long-term effects of severely reduced kidney function early in life. Cardiovascular changes are known to contribute considerably in adulthood to the severe complications of renal failure. In young chronic kidney disease patients, there is limited knowledge of subclinical cardiovascular disease. In this issue of Clinical Kidney Journal, Lalayiannis et al. describe significant structural and functional cardiovascular changes in a young cohort of kidney failure patients with glomerular filtration rate <30 mL/min/1.73 m². Among the 100 patients between 5 and 30 years of age included in the study, 84 presented with signs of cardiovascular disease. There is a need for long-term follow-up data on cardiovascular consequences of renal failure early in life and evaluation of prophylactic and therapeutic measures that can ameliorate the overall prognosis for these patients. We look forward to planned future long-term data from this cohort as well as increased focus in general on cardiovascular changes in young renal failure patients.