Haematocrit levels and left ventricular geometry: results of the MONICA Augsburg Echocardiographic Substudy

Better prognosis in surgical aortic valve replacement patients with lower red cell distribution width: A MIMIC-IV database study

BACKGROUND

Surgical aortic valve replacement (SAVR) currently stands as a primary surgical intervention for addressing aortic valve disease in patients. This retrospective study focused on the role of the red blood cell distribution width (RDW) in predicting adverse outcomes among SAVR patients.

METHODS

The subjects for this study were exclusively derived from the Medical Information Mart for Intensive Care database (MIMIC IV 2.0). Kaplan‒Meier (K-M) curves and Cox proportional hazards regression models were employed to assess the correlation between RDW, one-year mortality, and postoperative atrial fibrillation (POAF). The smooth-fitting curves were used to observe the relative risk (RR) of RDW in one-year mortality and POAF. Furthermore, time-dependent receiver operating characteristic (ROC) curves, the continuous-net reclassification index (NRI), and integrated discrimination improvement (IDI) were employed for comprehensive assessment of the prognostic value of RDW.

RESULTS

Analysis of RDW revealed a distinctive inverted U-shaped relationship with one-year mortality, while its association with POAF appeared nearly linear. Cox multiple regression models showed that RDW > 14.35%, along with preoperative potassium concentration and perioperative red blood cell transfusion, were significantly linked to one-year mortality (K-M curves, log-rank P < 0.01). Additionally, RDW was associated with both POAF and prolonged hospital stays (P < 0.05). There was no significant difference in length of stay in ICU. Notably, the inclusion of RDW in the predictive models substantially enhanced its performance. This was evidenced by the time-dependent ROC curve (AUC = 0.829), NRI (P< 0.05), IDI (P< 0.05), and K-M curves (log-rank P< 0.01).

CONCLUSIONS

RDW serves as a robust prognostic indicator for SAVR patients, offering a novel means of anticipating adverse postoperative events.

Chromium picolinate supplementation improves cardiac performance in hypoxic rats

BACKGROUND

Conditions associated with chronic hypoxia increase morbidity and mortality attributable to cardiovascular complications. Myocardial hypoxia is a common feature in several diseases including: stroke, infarction, anaemia, chronic lung diseases, obstructive sleep apnoea and cyanotic congenital heart defects. The present study was planned to investigate the cardiovascular effects of chronic intermittent hypoxia and its association with increased myocardial oxidative stress. In addition, to evaluate the protective effect of chromium supplementation, aiming at achieving an alternative that may enable to devise a therapy for hypoxic patients.

METHODS

Male rats were allocated into three groups: control group (normoxic), untreated hypoxic group (exposed to hypoxia 8 h/day, 5 days/week for 6 weeks) and hypoxic group supplemented with chromium picolinate (90 µg/kg/day by gavage). Rats were subjected to measurement of body weight, haematocrit value, mean arterial blood pressure, heart rate and ECG recording. Cardiac activities of isolated hearts were studied on Langendorff preparation under basal conditions and in response to ischaemia/reperfusion. Thereafter, cardiac weights were determined and cardiac tissue catalase activity as well as malondialdhyde level were assessed.

RESULTS

Significant results were obtained upon exposure to hypoxia including; low body weight, increased haematocrit, elevated blood pressure, left ventricular hypertrophy and impaired cardiac activities, basally and in response to ischaemia/reperfusion challenges, associated with increased oxidative stress in cardiac tissue. At the same time, chromium supplementation increased body weight, lowered blood pressure, reduced ventricular hypertrophy and significantly improved the cardiac performance.

CONCLUSION

Chromium supplementation confers protection against hypoxia-induced cardiovascular dysfunction by improvement of the antioxidant capacity.

Left ventricular geometry and electrocardiographic criteria in assessing left ventricular hypertrophy in sickle cell anemia patients

BACKGROUND

Left ventricular hypertrophy (LVH) is recognized as a cardiovascular risk factor and is a known consequence of sickle cell anemia (SCA). Abnormal left ventricular geometric patterns have been described but the determinants have not been well elucidated.

METHOD

Electrocardiography (ECG) and Echocardiography (ECHO) was done on subjects with SCA and hemoglobin A(HBA). Those with systemic hypertension were excluded. Voltages, durations, and intervals were measured as appropriate and recorded in a standard proforma. Analysis was made using a standard statistical software.

RESULTS

Eighty four people with SCA and 91 with HBA were recruited as cases and controls respectively. Subjects with SCA have more abnormal LV geometric patterns than those with HBA(p=0.000). Eccentric LVH(p=0.000) was more in SCA subjects while concentric LVH(p=0.054) and concentric remodeling(p=0.319) were not. Forty-one and fifty-two subjects with SCA and HBA respectively did ECGs. . Subjects with eccentric LVH had lower hip circumference, higher left atrial diameter, right atrial area, higher sokolow-lyon voltage sum, stroke volume and cardiac output. The Sokolow-Lyon voltage criteria at the traditional cut off point was not different between those with and without eccentric LVH. However, Sokolow-Lyon voltage criteria at a cut-off of ≥4.7mV detected eccentric LVH with a sensitivity of 60% and specificity of 83.3%.While Sokolow-Lyon voltage sum, stroke volume, right atrial area, and left atrial diameter correlated positively, pulse rate and hip circumference correlated inversely with eccentric LVH. Sokolow Lyon voltage sum was the independent determinant of eccentric LVH in this study.

CONCLUSION

Sickle cell anemia predisposes to abnormal LV geometric patterns, especially eccentric LVH. There may be a need to review the electrocardiographic cut off points for defining eccentric LVH in the SCA populace.

Chronic kidney disease measures for cardiovascular risk prediction

Chronic kidney disease (CKD) affects 15-20% of adults globally and causes various complications, one of the most important being cardiovascular disease (CVD). CKD has been associated with many CVD subtypes, especially severe ones like heart failure, independent of potential confounders such as diabetes and hypertension. There is no consensus in major clinical guidelines as to how to incorporate the two key measures of CKD (glomerular filtration rate and albuminuria) for CVD risk prediction. This is a critical missed opportunity to appropriately refine predicted risk and personalize prevention therapies according to CKD status, particularly since these measures are often already evaluated in clinical care. In this review, we provide an overview of CKD definition and staging, the subtypes of CVD most associated with CKD, major pathophysiological mechanisms, and the current state of CKD as a predictor of CVD in major clinical guidelines. We will introduce the novel concept of a "CKD Add-on", which allows the incorporation of CKD measures in existing risk prediction models, and the implications of taking into account CKD in the management of CVD risk.

Relationship Between Anemia and Sudden Cardiac Death in Patients With Severe Aortic Stenosis

Aortic stenosis (AS) is associated with significant morbidity and mortality, including sudden cardiac death (SCD). Anemia is a known risk factor for mortality in patients with AS. We sought to understand the prognostic implications between anemia and SCD in severe AS. The Mayo Clinic AS database includes 8,357 adults with severe AS (mean gradient ≥40 mm Hg, aortic valve area ≤1 cm², or peak aortic jet velocity ≥4 m/s) enrolled between January 1, 1995 and April 30, 2015. Survival and cause of death were ascertained from the National Death Index and SCD from medical records. We excluded patients with multiple valvular abnormalities, leaving 7,292 subjects. The median (interquartile range, [IQR]) age was 76 (68, 82) years with 56% male, and median (IQR) hemoglobin level was 12.9 (11.6, 14.1) g/dl. The frequency of anemia (hemoglobin <13.0g/dl for men, <12.0 g/dL for women) was 40%. During median (IQR) follow up of 4.4 (1.8, 8.1) years, 4,056 died (10-year survival 38%) including 225 with SCD (10-year cumulative incidence 5%). In a multivariate model including age, sex, body-mass index, hypertension, diabetes mellitus, myocardial infarction, estimated glomerular filtration rate, and time dependent aortic valve replacement, anemia was associated with increased all-cause mortality (hazard ratios 1.75, 95%CI 1.64, 1.87; p < 0.001) and increased SCD mortality (hazard ratios 1.42, 95%CI 1.07, 1.86; p = 0.01). In conclusions, anemia is a frequent finding in patients with severe AS and independently associated with increased all-cause mortality and SCD. Anemia may be a useful prognostic marker and a modifiable therapeutic target in managing patients with severe AS.

Impact of Hemoglobin Levels and Their Dynamic Changes on the Risk of Atrial Fibrillation: A Nationwide Population-Based Study

Anemia is a risk factor for cardiovascular disease, but its impact on new-onset atrial fibrillation (AF) is unclear. In this study, we investigated the effect of hemoglobin (Hb) levels and their changes on the risk of AF development in the general population of Korea. We retrospectively analyzed a cohort from the Korean National Health Insurance Service database and identified 9,686,314 subjects (49.8% male) without a history of AF, aged ≥40 years, and with Hb levels available for both first (2009-2010) and second (2011-2012) health checkups. These subjects were followed up until 2017 to determine AF development. The presence of anemia (Hb level <13 g/dL in men and <12 g/dL in women) was a significant risk factor for AF development. However, Hb levels showed a U-shaped association with incident AF after adjustment for cardiovascular risk factors. AF incidence was lowest at Hb levels of 14-14.9 g/dL in men and 12-12.9 g/dL in women. Among individuals with Hb levels within normal ranges (13-15.9 g/dL in men and 12-14.9 g/dL in women), both decrease and increase in Hb levels at the second measurement outside the normal ranges showed an elevation of AF risk by 11% and 21% for men and 3% and 36% for women, respectively, compared with those who maintained normal Hb levels. In conclusion, low or high Hb levels are associated with an increased risk of incident AF. This study suggests that maintaining Hb levels within the normal ranges confers a low risk of AF development.

Symmetric dimethylarginine, high-density lipoproteins and cardiovascular disease

Aims

The vascular effects of high-density lipoproteins (HDL) differ under certain clinical conditions. The composition of HDL is modified in patients with chronic kidney disease (CKD). As a consequence, uremic HDL induces endothelial dysfunction. We have previously shown that accumulation of symmetric dimethylarginine (SDMA) in HDL causes these adverse effects of HDL in CKD. The aim of the study is to determine the impact of the accumulation of SDMA on the association between HDL and mortality.

Methods and results

Mortality, renal function, serum SDMA and HDL-cholesterol (HDL-C) were assessed in the LURIC study including 3310 subjects undergoing coronary angiography. All-cause mortality was 30.0% during median follow-up of 9.9 years. Serum SDMA levels significantly predicted all-cause and cardiovascular mortality, and were significantly correlated with SDMA accumulation in HDL. Notably, higher serum SDMA was independently associated with lower cholesterol efflux (P = 0.004) as a measure of HDL functionality. In subjects with low SDMA levels, higher HDL-C was associated with significantly lower mortality. In contrast, in subjects with high SDMA, HDL-C was associated with higher mortality. These findings were confirmed in 1424 participants of the MONICA/KORA S3 cohort. Of note, we derived an algorithm allowing for calculation of biologically effective HDL-C' based on measured HDL-C and SDMA. We corroborated these clinical findings with invitro evidence showing that SDMA accumulation abolishes the anti-inflammatory and regenerative properties of HDL.

Conclusion

The data identify SDMA as a marker of HDL dysfunction. These findings highlight on the pivotal role of SDMA accumulation in HDL as a mediator of pre-mature cardiovascular disease in patients with CKD.

Hemoglobin, Albuminuria, and Kidney Function in Cardiovascular Risk: The ARIC (Atherosclerosis Risk in Communities) Study

BACKGROUND

Reduced estimated glomerular filtration rate (eGFR) and elevated urinary albumin-to-creatinine ratio (ACR) individually increase risk of cardiovascular disease (CVD). We hypothesized that these associations are stronger among people with abnormal (both low and high) hemoglobin levels.

METHODS AND RESULTS

Using 5801 participants with available hemoglobin measures of the ARIC (Atherosclerosis Risk in Community) study in 1996-1998, we explored the cross-sectional association of eGFR and ACR with hemoglobin levels and their longitudinal associations with CVD (heart failure, coronary heart disease, and stroke) risk through 2013. At baseline, 8.8% had anemia (<13 g/dL in men and <12 g/dL in women) and 7.2% had high hemoglobin (≥16 g/dL in men and ≥15 g/dL in women). The adjusted prevalence ratio of anemia was 2.12 (95% confidence interval, 1.59-2.82) for eGFR 30 to 59 compared with ≥90 mL/min per 1.73 m² and 1.45 (1.07-1.95) for ACR ≥30 compared with <10 mg/g. ACR ≥30 mg/g was also associated with high hemoglobin (prevalence ratio, 1.57 [1.12-2.19] compared with <10 mg/g). During follow-up, there were 1069 incident CVDs among 5098 CVD-free participants at baseline. In multivariable Cox models, lower eGFR, higher ACR, and anemia were each independently associated with CVD risk, with the association of low eGFR being slightly stronger in anemia (P-for-interaction, 0.072). There was no hemoglobin-ACR interaction; however, when CVD subtypes were analyzed separately, risk of coronary heart disease and stroke associated with high ACR was slightly stronger in high hemoglobin (P-for-interaction, 0.074).

CONCLUSIONS

Kidney function, albuminuria, and anemia were correlated and independently associated with CVD risk. Correlation and potential interaction for atherosclerotic CVD between albuminuria and high hemoglobin deserve further investigation.

Usefulness of the blood hematocrit level to predict development of heart failure in a community

Current data suggest that increases in hemoglobin may decrease nitric oxide and adversely affect vascular function. In the preclinical setting, these changes could precipitate the development of heart failure (HF). We hypothesized that higher hematocrit (HCT) would be associated with an increased incidence of new-onset HF in the community. We evaluated 3,523 participants (59% women) from the Framingham Heart Study who were 50 to 65 years old and free of HF. Participants were followed prospectively until an HF event, death, or the end of 20 years of follow up. HCT was subdivided into 4 gender-specific categories (women: HCT 36.0 to 40.0, 40.1 to 42.0, 42.1 to 45.0, >45.0; men: 39.0 to 44.0, 44.1 to 45.0, 45.1 to 49.0, >49.0). Gender-pooled multivariable Cox proportional hazards models were used to estimate the association of HCT with incident HF, adjusting for clinical risk factors. During the follow-up period (61,417 person-years), 217 participants developed HF (100 events in women). There was a linear increase in risk of HF across the 4 HCT categories (p for trend = 0.002). Hazards ratios for HF in the low-normal, normal, and high HCT categories were 1.27 (95% confidence interval 0.82 to 1.97), 1.47 (1.01 to 2.15), and 1.78 (1.15 to 2.75), respectively, compared to the lowest HCT category (p for trend <0.0001). Adjustment for interim development of other cardiovascular diseases and restriction of the sample to nonsmokers did not alter the results. In conclusion, higher levels of HCT, even within the normal range, were associated with an increased risk of developing HF in this long-term follow-up study.

Low serum magnesium concentrations predict increase in left ventricular mass over 5 years independently of common cardiovascular risk factors

OBJECTIVE

Left ventricular hypertrophy (LVH) is a significant predictor of adverse cardiovascular events. Experimental studies suggest a pathophysiological role of magnesium (Mg(2+)) in the development of arterial hypertension and LVH.

METHODS

In subjects with complete echocardiographic data from the population-based longitudinal "Study of Health in Pomerania" (n=1 348), the difference in left ventricular mass (LVM) over 5 years (echocardiography) was analyzed in relationship to serum Mg(2+) at baseline.

RESULTS

Mg(2+) at baseline (0.790 ± 0.003 mmol/l, mean ± SEM) inversely correlated with the difference in LVM over 5 years (p<0.0001, females: p<0.002, males: p<0.024). In the lowest Mg(2+)-quintile (Mg(2+)<=0.73 mmol/l), LVM (187.4 ± 3.1 g at baseline) increased by 14.9 ± 1.2 g, while in the highest Mg(2+)-quintile (Mg(2+)>=0.85 mmol/l) LVM (186.7 ± 3.4 g at baseline) decreased by -0.5 ± 2.8 g (p<0.0001 between quintiles). By multivariable analysis including several cardiovascular risk factors and antihypertensive treatment, serum Mg(2+) was associated with the increase in LVM at a statistically high significant level (p<0.0001). LVM after 5 years was significantly higher in subjects within the lower Mg(2+)-quintiles. This association remained highly significant after adjustment for several cardiovascular risk factors including arterial hypertension and diabetes mellitus.

CONCLUSIONS

Hypomagnesemia is one of the strongest predictors of gain in LVM over the following 5 years.

Chronic erythropoietin treatment affects different molecular pathways of diabetic cardiomyopathy in mouse

BACKGROUND

Recent studies in mice experimental models with acute ischaemic injury revealed that erythropoietin (EPO) has numerous tissue-protective effects in the heart, brain and kidneys. We therefore explored the tissue-protective properties of chronic EPO treatment in an experimental model of the db/db mouse with diabetic heart injury.

MATERIAL AND METHODS

We randomly treated 11 db/db mice with placebo (saline), 0.4 microg of the continuous erythropoietin receptor activator (CERA) per week (n = 11) or 1.2 microg CERA per week (n = 11) for 14 weeks, and analysed cardiac tissue. The lower CERA dose was a non-haematologically effective dose, whereas the second increased the haematocrit.

RESULTS

Compared with mice in the placebo group, CERA-treated mice had a reduction in TGF-beta(1) and collagen I expression in cardiac tissue (P < 0.01 vs. higher dose CERA). In addition, an increased expression of the pro-survival intracellular pathway p-AKT was observed (P < 0.05 vs. higher dose CERA). The values for the lower C.E.R.A had an intermediate nonsignificant effect. Furthermore, we were able to show that atrial natriuretic peptide (ANP) expression was increased in both CERA groups.

CONCLUSIONS

Chronic treatment with CERA protects cardiac tissue in diabetic animals, i.e. it inhibits molecular pathways of cardiac fibrosis, and the effects are dose-dependent.

[Kidney insufficiency and cardiovascular disease]

Cardiovascular disease (CVD) is the leading cause of mortality and morbidity in patients with chronic renal disease. Severe cardiac and arterial disorders such as left ventricular hypertrophy, coronary artery disease, and arteriosclerosis of the large vessels are already evident in early renal disease, even in young patients. Despite major advances in dialysis therapy and treatment options for acute coronary syndromes, mortality remains high--up to 10-30 times higher than in the general population. The increased risk for cardiovascular disorders results from the additive effect of traditional risk factors, volume overload, and endocrine and metabolic abnormalities in uremia. During the course of the renal disease, the progression of CVD disease manifestations significantly influences outcome. Thus, preventive measures and optimal treatment are mandatory and should be among the main targets of early management of patients with chronic renal disease.