Risk stratification for cardiac death in hemodialysis patients without obstructive coronary artery disease

The triglyceride-glucose index predicts 1-year major adverse cardiovascular events in end-stage renal disease patients with coronary artery disease

BACKGROUND

The triglyceride-glucose (TyG) index has been suggested as a dependable indicator for predicting major adverse cardiovascular events (MACE) in individuals with cardiovascular conditions. Nevertheless, there is insufficient data on the predictive significance of the TyG index in end-stage renal disease (ESRD) patients with coronary artery disease (CAD).

METHODS

This study, conducted at multiple centers in China, included 959 patients diagnosed with dialysis and CAD from January 2015 to June 2021. Based on the TyG index, the participants were categorized into three distinct groups. The study's primary endpoint was the combination of MACE occurring within one year of follow-up, including death from any cause, non-fatal myocardial infarction, and non-fatal stroke. We assessed the association between the TyG index and MACE using Cox proportional hazard models and restricted cubic spline analysis. The TyG index value was evaluated for prediction incrementally using C-statistics, continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

RESULTS

The three groups showed notable variations in the risk of MACE (16.3% in tertile 1, 23.5% in tertile 2, and 27.2% in tertile 3; log-rank P = 0.003). Following complete adjustment, patients with the highest TyG index exhibited a notably elevated risk of MACE in comparison to those in the lowest tertile (hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.14-2.35, P = 0.007). Likewise, each unit increase in the TyG index correlated with a 1.37-fold higher risk of MACE (HR 1.37, 95% CI 1.13-1.66, P = 0.001). Restricted cubic spline analysis revealed a connection between the TyG index and MACE (P for nonlinearity > 0.05). Furthermore, incorporating the TyG index to the Global Registry of Acute Coronary Events risk score or baseline risk model with fully adjusted factors considerably enhanced the forecast of MACE, as demonstrated by the C-statistic, continuous NRI, and IDI.

CONCLUSIONS

The TyG index might serve as a valuable and dependable indicator of MACE risk in individuals with dialysis and CAD, indicating its potential significance in enhancing risk categorization in clinical settings.

Association of triglyceride-glucose index with coronary severity and mortality in patients on dialysis with coronary artery disease

BACKGROUND

The triglyceride-glucose (TyG) index is validated as a reliable biomarker of insulin resistance and an independent predictor of cardiovascular prognosis. However, the prognostic value of the TyG index in patients on dialysis with coronary artery disease (CAD) remained unexplored. This study aimed to determine the association between the TyG index and CAD severity and mortality in these patients.

METHODS

A total of 1061 dialysis patients with CAD were enrolled in this multi-center cohort study from January 2015 to June 2021. The extent and severity of CAD were evaluated using the multivessel disease and Gensini score (GS). Patients were followed up for all-cause death and cardiovascular death.

RESULTS

The multivariable logistic regression model indicated that the TyG index was significantly associated with multivessel disease (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.18-1.94, P = 0.001), and high GS (OR 1.33, 95% CI 1.10-1.61, P = 0.003). After adjusting for baseline risk factors, the hazards of all-cause death and cardiovascular death were 1.23 (95% CI 1.06-1.43, P = 0.007), and 1.33 (95% CI 1.11-1.59, P = 0.002), independent of CAD severity. Restricted cubic spline analysis identified a dose-response association between the TyG index and both CAD severity and mortality (all P for nonlinearity > 0.05). When modeling the TyG index as a categorical variable, these independent associations remained. Subgroup analyses did not substantially modify the results. Furthermore, incorporating the TyG index into the existing risk prediction model improved the predictive accuracy for all-cause death and cardiovascular death, as evaluated by C-statistic, continuous net reclassification improvement, and integrated discrimination improvement.

CONCLUSIONS

In patients on dialysis with CAD, the TyG index was significantly associated with more severe CAD as well as mortality. These results highlight the clinical importance of the TyG index for assessing CAD severity and risk stratification in patients on dialysis with CAD.

Prevalence and clinical outcomes of triglyceride deposit cardiomyovasculopathy among haemodialysis patients

OBJECTIVE

To evaluate the effect of triglyceride deposit cardiomyovasculopathy (TGCV) on the cardiovascular outcomes in haemodialysis (HD) patients with suspected coronary artery disease (CAD).

METHODS

This retrospective single-centre observational study included data from the cardiac catheter database of Narita Memorial Hospital between April 2011 and March 2017. Among 654 consecutive patients on HD, the data for 83 patients with suspected CAD who underwent both [123I]-β-methyl-iodophenyl-pentadecanoic acid scintigraphy and coronary angiography were analysed. Patients were divided into three groups: definite TGCV (17 patients), probable TGCV (22 patients) and non-TGCV control group (44 patients). The primary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction and non-fatal stroke assessed for up to 5 years of follow-up.

RESULTS

The prevalence of definite TGCV was approximately 20% and 2.6% among consecutive HD patients with suspected CAD and among all HD patients, respectively. At the end of the median follow-up period of 4.7 years, the primary endpoint was achieved in 52.9% of the definite TGCV patients (HR, 7.45; 95% CI: 2.28 to 24.3; p<0.001) and 27.3% of the probable TGCV patients (HR, 3.28; 95% CI: 0.93 to 11.6; p=0.066), compared with that in 9.1% of the non-TGCV control patients. Definite TGCV was significantly and independently associated with cardiovascular mortality and outcomes among HD patients in all multivariate models.

CONCLUSIONS

TGCV is not uncommon in HD patients and is associated with an increased risk of cardiovascular events including cardiovascular death. Thus, TGCV might be a potential therapeutic target.

Increased Serum Parathyroid Hormone, Osteocalcin and Alkaline Phosphatase Are Associated with a Long-Term Adverse Cardiovascular Outcome after Coronary Artery Bypass Graft Surgery

Despite the fact that an association of osteopoenia/osteoporosis with elevated risk of coronary artery calcification (CAC) and coronary atherosclerosis (CA) is well-established, it remains unclear whether bone turnover markers can be employed in long-term prognostication of such patients. Here we measured serum calcium, phosphate, calcitonin, parathyroid hormone (PTH), osteoprotegerin, osteocalcin, osteopontin, alkaline phosphatase and its bone isoenzyme, subsequently correlating them with an adverse cardiovascular outcome after 3 years of follow-up. The extent of brachiocephalic artery stenosis, CA, or CAC, as well as prevalence of osteopoenia/osteoporosis before the coronary artery bypass graft (CABG) surgery, did not differ between outcome groups, suggesting that subtle molecular mechanisms might be involved in determining the outcome rather than clinical or subclinical disease. After stepwise logistic regression, serum osteocalcin > 26.8 ng/mL and PTH > 49.1 pg/mL were independent predictors of an adverse outcome. Serum ionised calcium correlated with multivessel coronary artery disease; moreover, patients with severe CA (SYNTAX score > 21) had higher serum ionised calcium than those with mild CA. Likewise, serum alkaline phosphatase was associated with severe CA and CAC (Agatston score > 400). In conclusion, serum PTH, osteocalcin, and alkaline phosphatase are associated with an adverse cardiovascular outcome 3 years after CABG surgery regardless of osteopoenia/osteoporosis, coronary/peripheral atherosclerosis, and CAC.

Incidence of sudden cardiac death in adults with end-stage renal disease: a systematic review and meta-analysis

BACKGROUND

Although sudden cardiac death (SCD) is recognized as a distinct cause of death in patients with end stage renal disease (ESRD), its incidence has not been well summarized.

METHODS

We performed a systematic review and meta-analysis of the literature based on a protocol developed a priori. We searched MEDLINE and EMBASE (inception to March 2015) for randomized controlled trials and cohort studies reporting the incidence of SCD in adult patients with ESRD on hemodialysis or peritoneal dialysis. We collected data on number of SCD as well as the definition of SCD for each individual study. A random-effects model was used to summarize the incidence of SCD. We conducted subgroup analyses to explore sources of heterogeneity.

RESULTS

Forty two studies (n = 80,382 patients) were included in the meta-analysis. The incidence of SCD among adults with ESRD ranged from 0.4 to 10.04 deaths per 100 person-years. The definitions and assessment of SCD varied across the included studies. There was evidence of significant heterogeneity (I(2) = 98; p < 0.001), which was not explained by subgroup analyses stratified by mean age, proportion of hypertensive or diabetic patients, follow-up time, study size, or type of cohort studied.

CONCLUSION

Current estimates of the incidence of SCD among adults with ESRD vary widely. There is a need for further studies to more accurately estimate the incidence of SCD in patients with ESRD.

Effects of intravenous l-carnitine on myocardial fatty acid imaging in hemodialysis patients: responders or non-responders to l-carnitine

We investigated whether chronic intravenous administration of l-carnitine could improve myocardial fatty acid imaging in patients on maintenance hemodialysis. We enrolled 72 hemodialysis patients who had impaired myocardial fatty acid imaging and left ventricular dysfunction not based on coronary lesion. l-Carnitine (1,000 mg) was intravenously administered after dialysis for 1 year to 36 participants (Carnitine group), while not in the other 36 participants (Control group). Single-photon emission computed tomography (SPECT) using an iodinated fatty acid analogue, BMIPP, was performed. Uptake on SPECT images was graded in 17 segments on a five-point scale (0, normal; 4, absent) and assessed as BMIPP summed scores. During follow-up, 19 participants were discontinued from the study, and 53 participants (65 ± 12 years: 27 carnitine, 26 control) were analyzed. The mean BMIPP summed scores 1 year after carnitine administration did not differ from that before in the carnitine group, nor from that in the control group. However, improved SPECT (Changes in BMIPP summed scores <−20%) was found in 7 (25.9%) participants in the carnitine, whereas in 2 (7.7%) in the control group. Multivariate logistic analysis showed the improved SPECT was inversely associated with baseline serum albumin levels (1 g/L: odds ratio, 0.669); the cut-off was 35 g/L. Chronic intravenous l-carnitine might improve myocardial fatty acid imaging in a selected group of hemodialysis patients with hypoalbuminemia.

Focal impairment in myocardial fatty acid imaging in the left anterior descending artery area, a strong predictor for cardiac death in hemodialysis patients without obstructive coronary artery disease

Purpose

We investigated whether impaired patterns of myocardial fatty acid imaging were associated with cardiac death in dialysis patients without coronary lesions.

Methods

We prospectively enrolled 155 hemodialysis patients without obstructive coronary artery disease, who had been examined by single-photon emission computed tomography (SPECT) using the iodinated fatty acid analogue BMIPP. Uptake of BMIPP on SPECT was graded in 17 segments on a five-point scale (0, normal; 4, absent) and assessed as BMIPP summed scores. Of the enrolled 155 participants, we analyzed 95 who had BMIPP summed scores ≥ 6 (52 men and 43 women, 65 ± 11 years). BMIPP scores ≥ 2 in ≥ 2 consecutive segments in SPECT were defined as focal, and the others as non-focal pattern.

Results

Of 95 participants analyzed, 42 (44.2 %) showed focal and 53 (55.8 %) non-focal type. During follow-up for 5.1 ± 2.0 years, 42 died of cardiac events. The occurrence of cardiac death was higher in the focal than in the non-focal group (30/42 [71.4 %] versus 12/53 [22.6 %], p = 0.001). In stepwise Cox hazard analysis, focal pattern was associated with cardiac death (hazard ratio 2.266), independent of impairment of BMIPP SPECT (BMIPP summed scores ≥ 12). The predictive potential of BMIPP SPECT for cardiac death was higher (p < 0.001) in the left anterior descending artery area compared with other coronary territories.

Conclusions

Focal impairment in myocardial fatty acid imaging in the left anterior descending area may strongly predict cardiac death in this population.

Improvement of myocardial fatty acid metabolism by oral nicorandil in hemodialysis patients without coronary artery disease

BACKGROUND

We investigated the potential of oral nicorandil to improve myocardial fatty acid metabolism assessed by single-photon emission computed tomography (SPECT) using (123)I-β-methyliodophenyl pentadecanoic acid (BMIPP) in hemodialysis patients without obstructive coronary artery disease (CAD).

METHODS

This study was based on a cohort study of 155 hemodialysis patients with angiographic absence of obstructive CAD, with analysis performed in 100 propensity-matched patients (54 men and 46 women, 64 ± 10 years); 50 with oral administration of nicorandil (15 mg/d, nicorandil group) and 50 without (control). BMIPP SPECT was performed every year after angiography. Uptake on SPECT was graded in 17 segments on a five-point scale (0 normal, 4 absent) and assessed as BMIPP summed scores (SS).

RESULTS

Over a mean follow-up period of 5.3 ± 1.9 years, we observed 25 cardiac deaths among 100 propensity-matched patients. Myocardial uptake of BMIPP in SPECT improved in the nicorandil group compared with the control group from 2 years of administration. In Kaplan-Meier survival analyses, free survival rate from cardiac death was higher in patients with a BMIPP SS improvement rate of ≥20% compared to those with ≥0% <20% or with <0% BMIPP SS improvement rate. At multiple logistic analysis, a ≥20% BMIPP SS improvement rate was positively associated with serum albumin concentration and oral nicorandil.

CONCLUSIONS

Long-term oral nicorandil may inhibit cardiac death by improving myocardial fatty acid metabolism in hemodialysis patients without obstructive CAD.

Myocardial perfusion imaging for predicting cardiac events in Japanese patients with advanced chronic kidney disease: 1-year interim report of the J-ACCESS 3 investigation

PURPOSE

Whether myocardial perfusion imaging (MPI) can predict cardiac events in patients with advanced conservative chronic kidney disease (CKD) remains unclear.

METHODS

The present multicenter prospective cohort study aimed to clarify the ability of MPI to predict cardiac events in 529 patients with CKD and estimated glomerular filtration rates (eGFR) < 50 ml/min per 1.73(2) without a definitive diagnosis of coronary artery disease. All patients were assessed by stress-rest MPI with (99m)Tc-tetrofosmin and analyzed using summed defect scores and QGS software. Cardiac events were analyzed 1 year after registration.

RESULTS

Myocardial perfusion abnormalities defined as summed stress score (SSS) ≥4 and ≥8 were identified in 19 and 7 % of patients, respectively. At the end of the 1-year follow-up, 33 (6.2 %) cardiac events had occurred that included cardiac death, sudden death, nonfatal myocardial infarction, and hospitalization due to heart failure. The event-free rates at that time were 0.95, 0.90, and 0.81 for groups with SSS 0-3, 4-7, and ≥8, respectively (p = 0.0009). Thus, patients with abnormal SSS had a higher incidence of cardiac events. Multivariate Cox regression analysis showed that SSS significantly impacts the prediction of cardiac events independently of eGFR and left ventricular ejection fraction.

CONCLUSION

MPI would be useful to stratify patients with advanced conservative CKD who are at high risk of cardiac events without adversely affecting damaged kidneys.

Clinical potential of oral nicorandil to improve myocardial fatty acid metabolism after percutaneous coronary intervention in hemodialysis patients

BACKGROUND/AIMS

The assessment of myocardial fatty acid metabolism impairment by single-photon emission computed tomography (SPECT) using (123)I-β-methyliodophenyl-pentadecanoic acid (BMIPP) might predict the risk of cardiac death in hemodialysis patients. We investigated the potential of oral nicorandil to improve myocardial fatty acid metabolism after percutaneous coronary intervention (PCI) in this population.

METHODS

We evaluated 128 hemodialysis patients who had obtained coronary revascularization by PCI (90 men and 38 women, 66 ± 9 years). Participants for the analysis were randomly assigned to either the nicorandil (n = 63) or control group (n = 65). BMIPP SPECT was performed every year after coronary revascularization by PCI. Uptake on SPECT was graded in 17 segments on a 5-point scale (0, normal; 4, absent) and assessed as BMIPP summed scores (SS).

RESULTS

The incidence of cardiac death was lower (p = 0.004) in the nicorandil group (7/63, 11.1%) than in the control group (21/65, 32.3%) during a mean follow-up of 2.7 ± 1.4 years. BMIPP SS reduction rates improved in the nicorandil group compared with the control group from 3 years of administration. In Kaplan-Meier analyses, free survival rate of cardiac death was higher in patients with a ≥20% BMIPP SS reduction rate as compared with those with a <20% BMIPP SS reduction rate (p = 0.0001). In multiple logistic analysis, oral administration of nicorandil was associated with ≥20% reduction rates of BMIPP SS (odds ratio 2.823, p = 0.011).

CONCLUSION

Long-term oral administration of nicorandil may improve impaired myocardial fatty acid metabolism after coronary revascularization by PCI in hemodialysis patients.

Ischaemic memory imaging using metabolic radiopharmaceuticals: overview of clinical settings and ongoing investigations

"Ischaemic memory" is defined as a prolonged functional and/or biochemical alteration remaining after a particular episode of severe myocardial ischaemia. The biochemical alteration has been reported as metabolic stunning. Metabolic imaging has been used to detect the footprint left by previous ischaemic episodes evident due to delayed recovery of myocardial metabolism (persistent dominant glucose utilization with suppression of fatty acid oxidation). β-Methyl-p-[(123)I]iodophenylpentadecanoic acid (BMIPP) is a single-photon emission computed tomography (SPECT) radiotracer widely used for metabolic imaging in clinical settings in Japan. In patients with suspected coronary artery disease but no previous myocardial infarction, BMIPP has shown acceptable diagnostic accuracy. In particular, BMIPP plays an important role in the identification of prior ischaemic insult in patients arriving at emergency departments with acute chest pain syndrome. Recent data also show the usefulness of (123)I-BMIPP SPECT for predicting cardiovascular events in patients undergoing haemodialysis. Similarly, SPECT or PET imaging with (18)F-FDG injected during peak exercise or after exercise under fasting conditions shows an increase in FDG uptake in postischaemic areas. This article will overview the roles of ischaemic memory imaging both under established indications and in ongoing investigations.

Microalbuminuria predicts silent myocardial ischaemia in type 2 diabetes patients

PURPOSE

Myocardial ischaemia is frequently silent in patients with type 2 diabetes. Although it has been proposed as a potential screening tool, the role of myocardial perfusion single photon emission computed tomography (MPS) has recently been questioned, due to the low prevalence of positive scans and the low rate of cardiac events. The aim of this study was to assess if pretest clinical variables can identify a subgroup of asymptomatic patients with type 2 diabetes at risk of silent myocardial ischaemia and a subsequent poor outcome

METHODS

This prospective study included 77 patients (50 men, mean age 63 ± 9 years) with type 2 diabetes and no known coronary artery disease (CAD) or angina pectoris who underwent gated MPS to screen for CAD between March 2006 and October 2008. MPS images were interpreted using a semiquantitative visual 20-segment model to define summed stress, rest and difference scores. Ischaemia was defined as a sum difference score (SDS) ≥2. Patients were followed-up (median 4.1 years, range 0.8 - 6.1 years) and cardiac hard events (cardiac death or nonfatal myocardial infarction) were recorded.

RESULTS

Silent ischaemia was detected in 25 of the 77 patients (32 %). Specifically, 10 patients (13 %) had mild ischaemia (SDS 2 to ≤4) and 15 patients (19 %) had severe ischaemia (SDS >4). In univariate binary logistic analysis, microalbuminuria was the only significant predictor of silent ischaemia on MPS (odds ratio 4.42, 95 % CI 1.27 - 15.40; P = 0.019). The overall accuracy of microalbuminuria for predicting silent ischaemia was 71.4 % and was 89.6 % for predicting severe ischaemia. Kaplan-Meier curves showed no significant group differences in 5-year cardiac event-free survival between patients with and those without microalbuminuria, or between patients with SDS ≥2 and those with SDS <2. In contrast, 5-year event-free survival was significantly lower in patients with SDS >4 than in patients with SDS ≤4: 55.6 % (95 % CI 39.0 - 72.2 %) vs. 94.5 % (95 % CI: 91.4 - 97.6 %), respectively (Breslow test, chi-square 20.9, P < 0.001). Median cardiac event-free survival was not observed in the whole group, while the 25th percentile of cardiac event-free survival was reached only in patients with SDS >4 (2.3 years). In univariate Cox regression analysis, SDS >4 predicted cardiac event-free survival (hazard ratio 12.87, 95 % CI 2.86 - 27.98; P = 0.001), while SDS ≥2 did not (hazard ratio 2.78, 95 % CI 0.62 - 12.46, P = 0.16).

CONCLUSION

In this group of patients with type 2 diabetes, microalbuminuria was the only predictor of silent ischaemia on MPS. Assessment of microalbuminuria should be routinely considered among the first risk stratification steps for CAD in patients with type 2 diabetes, even though severe ischaemia on MPS is a major predictor of cardiac event-free survival.

Oral nicorandil for prevention of cardiac death in hemodialysis patients without obstructive coronary artery disease: a propensity-matched patient analysis

BACKGROUND/AIMS

We examined the potential of oral administration of nicorandil for protecting against cardiac death in hemodialysis patients without obstructive coronary artery disease.

METHODS

This study was based on a cohort study of 155 hemodialysis patients with angiographic absence of obstructive coronary lesions, with analysis performed in 100 propensity-matched patients (54 men and 46 women, 64 ± 10 years), including 50 who received oral administration of nicorandil (15 mg/day, nicorandil group) and 50 who did not (control). The efficacy of nicorandil in preventing cardiac death was investigated.

RESULTS

Over a mean follow-up period of 5.3 ± 1.9 years, we observed 25 cardiac deaths among 100 propensity-matched patients, including 6 due to acute myocardial infarction, 11 due to heart failure, and 8 due to sudden cardiac death. The incidence of cardiac death was lower (p < 0.001) in the nicorandil group (4/50, 8%) than in the control (21/50, 42%). On multivariate Cox hazard analysis, cardiac death was inversely associated with oral nicorandil (hazard ratio, 0.123; p = 0.0002). On Kaplan-Meier analysis, cardiac death-free survival rates at 5 years were higher in the nicorandil group than in the control group (91.4 vs. 66.4%).

CONCLUSION

Oral nicorandil may inhibit cardiac death of hemodialysis patients without obstructive coronary artery disease.