The heart rate response to adenosine: a simple predictor of adverse cardiac outcomes in asymptomatic patients with type 2 diabetes

Precision prognostics for cardiovascular disease in Type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

Precision medicine has the potential to improve cardiovascular disease (CVD) risk prediction in individuals with Type 2 diabetes (T2D).

METHODS

We conducted a systematic review and meta-analysis of longitudinal studies to identify potentially novel prognostic factors that may improve CVD risk prediction in T2D. Out of 9380 studies identified, 416 studies met inclusion criteria. Outcomes were reported for 321 biomarker studies, 48 genetic marker studies, and 47 risk score/model studies.

RESULTS

Out of all evaluated biomarkers, only 13 showed improvement in prediction performance. Results of pooled meta-analyses, non-pooled analyses, and assessments of improvement in prediction performance and risk of bias, yielded the highest predictive utility for N-terminal pro b-type natriuretic peptide (NT-proBNP) (high-evidence), troponin-T (TnT) (moderate-evidence), triglyceride-glucose (TyG) index (moderate-evidence), Genetic Risk Score for Coronary Heart Disease (GRS-CHD) (moderate-evidence); moderate predictive utility for coronary computed tomography angiography (low-evidence), single-photon emission computed tomography (low-evidence), pulse wave velocity (moderate-evidence); and low predictive utility for C-reactive protein (moderate-evidence), coronary artery calcium score (low-evidence), galectin-3 (low-evidence), troponin-I (low-evidence), carotid plaque (low-evidence), and growth differentiation factor-15 (low-evidence). Risk scores showed modest discrimination, with lower performance in populations different from the original development cohort.

CONCLUSIONS

Despite high interest in this topic, very few studies conducted rigorous analyses to demonstrate incremental predictive utility beyond established CVD risk factors for T2D. The most promising markers identified were NT-proBNP, TnT, TyG and GRS-CHD, with the highest strength of evidence for NT-proBNP. Further research is needed to determine their clinical utility in risk stratification and management of CVD in T2D.

Precision Prognostics for Cardiovascular Disease in Type 2 Diabetes: A Systematic Review and Meta-analysis

Background Precision medicine has the potential to improve cardiovascular disease (CVD) risk prediction in individuals with type 2 diabetes (T2D). Methods We conducted a systematic review and meta-analysis of longitudinal studies to identify potentially novel prognostic factors that may improve CVD risk prediction in T2D. Out of 9380 studies identified, 416 studies met inclusion criteria. Outcomes were reported for 321 biomarker studies, 48 genetic marker studies, and 47 risk score/model studies. Results Out of all evaluated biomarkers, only 13 showed improvement in prediction performance. Results of pooled meta-analyses, non-pooled analyses, and assessments of improvement in prediction performance and risk of bias, yielded the highest predictive utility for N-terminal pro b-type natriuretic peptide (NT-proBNP) (high-evidence), troponin-T (TnT) (moderate-evidence), triglyceride-glucose (TyG) index (moderate-evidence), Genetic Risk Score for Coronary Heart Disease (GRS-CHD) (moderate-evidence); moderate predictive utility for coronary computed tomography angiography (low-evidence), single-photon emission computed tomography (low-evidence), pulse wave velocity (moderate-evidence); and low predictive utility for C-reactive protein (moderate-evidence), coronary artery calcium score (low-evidence), galectin-3 (low-evidence), troponin-I (low-evidence), carotid plaque (low-evidence), and growth differentiation factor-15 (low-evidence). Risk scores showed modest discrimination, with lower performance in populations different from the original development cohort. Conclusions Despite high interest in this topic, very few studies conducted rigorous analyses to demonstrate incremental predictive utility beyond established CVD risk factors for T2D. The most promising markers identified were NT-proBNP, TnT, TyG and GRS-CHD, with the highest strength of evidence for NT-proBNP. Further research is needed to determine their clinical utility in risk stratification and management of CVD in T2D.

Reduced coronary flow velocity reserve and blunted heart rate reserve identify a higher risk group in patients with chest pain and negative emergency department evaluation

To estimate the prognostic value of stress echo (SE) with the assessment of coronary flow velocity reserve (CFVR) and heart rate reserve (HRR) in patients admitted for chest pain with non-diagnostic EKG, negative troponin, and without inducible regional wall motion abnormalities (RWMA). 658 patients (age 67 ± 12 years) admitted to our Emergency Department with chest pain, non-diagnostic EKG, and negative serial troponin underwent dipyridamole (0.84 mg/kg in 6') SE with simultaneous assessment of RWMA, CFVR in the left anterior descending artery, and HRR as peak/rest heart rate. The outcome measure was all-cause mortality. Of the 658 patients initially enrolled, 20 (3%) showed RWMA during SE and were referred to ischemia-driven revascularization. In the remaining 638, CFVR was abnormal (≤ 2.0) in 148 patients (23%). HRR was abnormal (≤ 1.22 in patients in sinus rhythm, or ≤ 1.17 in patients with permanent atrial fibrillation) in 196 patients (31%). During a follow-up of 7.3 ± 4.3 years, 151 (24%) patients died. Survival at 8 years was 93% in patients with normal CFVR and HRR, 76% in patients with abnormal CFVR only, 73% in patients with abnormal HRR only, and 38% in those with abnormal CFVR and HRR (p < 0.0001). At multivariable analysis, abnormal CFVR (HR 1.49, 95% CI 1.05-2.10, p = 0.02) and abnormal HRR (HR 2.01, 95% CI 1.43-2.84, p < 0.0001) were independent predictors of survival. In admitted patients with non-ischemic EKG, negative serial troponin, and without RWMA during dipyridamole SE, a reduced CFVR and blunted HRR independently identify a subset with worse survival in the long term. Upper panel: Color and pulsed-wave Doppler with the electrocardiographic lead tracing of Four different response patterns (from left to right): normal CFVR and HRR; normal CFVR, abnormal HRR; abnormal CFVR, normal HRR; abnormal CFVR and HRR. Lower panel: The annualized death rate for each of the four groups with negative SE for RWMA and stratified according to the presence of CFVR and HRR: none, one, or two abnormalities.

Relationship between heart rate response and cardiac innervation in patients with suspected or known coronary artery disease

BACKGROUND

Chronotropic response to pharmacological stress test is blunted in patients with autonomic neuropathy. The relationship between heart rate (HR) changes during pharmacological stress test and cardiac autonomic dysfunction has not been fully investigated. We assessed the potential interplay between HR response (HRR) and myocardial innervation in patients with suspected or known coronary artery disease (CAD).

METHODS AND RESULTS

We studied 71 patients with suspected or known CAD referred to pharmacological stress myocardial perfusion imaging and 123I metaiodobenzylguanidine (123I-MIBG) cardiac scintigraphy. HRR was calculated as the maximum percent change from baseline according to the formula: (peak HR - rest HR)/rest HR × 100. 123I-MIBG heart-to-mediastinum (H/M) ratio was calculated and a late H/M ratio < 1.6 was considered abnormal. HRR progressively decreased with decreasing late H/M ratio (P for trend = 0.02) and a significant correlation between HRR and late H/M ratio (P = 0.03) was observed. The addition of HRR to a model including age, diabetes, known CAD, left ventricular ejection fraction, and stress-induced ischemia added incremental value in predicting an abnormal late H/M ratio, increasing the global chi-square from 8.09 to 13.8 (P = 0.02).

CONCLUSIONS

The relationship between HRR and cardiac sympathetic innervation in patients with suspected or known CAD confirms a strong interplay between cardiac response to stress tests and cardiac autonomic activation. This finding suggests that HRR may be used as a surrogate for assessing cardiac sympathetic function.

The prognostic value of heart rate response during vasodilator stress myocardial perfusion imaging in patients with end-stage renal disease undergoing renal transplantation

BACKGROUND

In asymptomatic end-stage renal disease (ESRD) patients undergoing vasodilator stress myocardial perfusion imaging (MPI) prior to renal transplantation (RT), the impact of pre-transplant heart rate response (HRR) to vasodilator stress on post-RT outcomes is unknown.

METHODS

We analyzed a retrospective cohort of asymptomatic patients with ESRD who underwent a vasodilator stress SPECT-MPI and subsequently received RT. Blunted HRR was defined as HRR <28% for regadenoson stress and <20% for adenosine stress. The primary endpoint was major adverse cardiac events (MACE), defined as cardiac death or myocardial infarction. Clinical risk was assessed using the sum of risk factors set forth by the AHA/ACCF consensus statement on the assessment of RT candidates.

RESULTS

Among 352 subjects, 140 had an abnormal pre-transplant HRR. During a mean follow-up of 3.2 ± 2.0 years, 85 (24%) MACEs were observed. Blunted HRR was associated with increased MACE risk (hazard ratio 1.72; 95% confidence interval 1.12-2.63, P = 0.013), and remained significant after adjustment for gender, sum of AHA/ACCF risk factors, summed stress score, baseline heart rate, and β-blocker use. HRR was predictive of MACE in patients with normal MPI and irrespective of clinical risk. Blunted HRR was associated with a significant increase in post-operative (30-day) MACE risk (17.9% vs 8.5%; P = 0.009).

CONCLUSION

In asymptomatic ESRD patients being evaluated for RT, a blunted pre-transplant HRR was predictive of post-RT MACE. HRR may be a valuable tool in the risk assessment of RT candidates.

Association between plasma homocysteine levels and end-organ damage in newly diagnosed type 2 diabetes mellitus patients

PURPOSE

The aim of the present study was to investigate the association between plasma homocysteine (Hcy) levels and carotid, cardiac, and renal end-organ damage in newly diagnosed type 2 diabetes mellitus (T2DM) patients.

METHODS

Newly diagnosed normotensive T2DM patients (n = 390) were enrolled in this study. The patients were not taking any medications over the duration of the study. The left ventricular mass index (LVMI), carotid intima media thickness (CIMT), and creatinine levels and 24-h microalbuminuria were used to determine cardiac, carotid, and kidney end-organ diseases, respectively.

RESULTS

Using univariate logistic regression analysis; age, 24-h microalbuminuria, fasting blood glucose, CIMT, creatinine level, and LVMI were found to be significantly associated with the Hcy level. When those six variables were included in a multivariate regression model, CIMT, LVMI, and creatinine were found to be significantly associated with the Hcy level. We determined that an Hcy level >12.5 µmol/L was predictive of high LVMI, with a sensitivity of 70.1% and a specificity of 68%. An Hcy level >13.5 µmol/L was predictive of high CIMT, with a sensitivity of 67.5% and a specificity of 63.1%.

CONCLUSION

In this study, LVMI, CIMT, and creatinine level were positively correlated with the Hcy level. We believe that the Hcy level may be a useful predictor of end-organ damage, including cardiac, carotid, and renal diseases, in newly diagnosed T2DM patients.

Prognostic value of heart rate response during regadenoson stress myocardial perfusion imaging in patients with end stage renal disease

BACKGROUND

Blunted heart rate response (HRR) to vasodilator stress agents is associated with worse outcomes. There are limited data assessing the effect of impaired HRR to regadenoson among patients with end-stage renal disease (ESRD) undergoing stress myocardial perfusion imaging (MPI).

METHODS

We prospectively followed patients with ESRD enrolled in the ASSUAGE and ASSUAGE-CKD trials. HRR was defined as 100*(peak stress heart rate-resting heart rate)/resting heart rate. Study cohort was dichotomized to blunted and normal HRR groups according to an established median HRR value <28% or ≥28%, which were propensity-score matched based on 22 clinical and imaging covariates. The Primary endpoint was all-cause death. The secondary cardiac-specific endpoints included: (1) the composite endpoint of cardiac death or myocardial infarction; (2) the composite endpoint of cardiac death, myocardial infarction, or late (>90 days) coronary revascularization.

RESULTS

There were 303 patients followed for 35 ± 10 months. In the entire cohort, there was a stepwise increase in the rates of death and all secondary endpoints with worsening HRR (P values ≤.001). Blunted HRR (<28%) was associated with increased risk of death (unadjusted hazard ratio 4.10 [1.98-8.46], P < .001) and all secondary endpoints (P ≤ .001). After multivariate adjustment, HRR remained an independent predictor of mortality and secondary endpoints whether used as continuous or dichotomous variable, and added incremental prognostic value for all-cause death (P = .046). Blunted HRR was associated with increased event rate among patients with normal myocardial perfusion (P = .001) and abnormal perfusion (P = .053). In the propensity-matched cohort of 132 patients (66 in each group), blunted HRR was associated with significant increase in all-cause death (21% vs. 5%, HR 5.09 [1.46-17.7], P=.011), and similarly for the secondary endpoints.

CONCLUSION

Blunted HRR (<28%) to regadenoson is a strong and independent predictor of death and cardiovascular events in patients with ESRD and adds incremental prognostic value.

The prognostic value of non-perfusion variables obtained during vasodilator stress myocardial perfusion imaging

Myocardial perfusion imaging (MPI) is an established diagnostic test that provides useful prognostic data in patients with known or suspected coronary artery disease. In more than half of the patients referred for stress testing, vasodilator stress is used in lieu of exercise. Unlike exercise, vasodilator stress does not provide information on exercise and functional capacity, heart rate recovery, and chronotropy, and ECG changes are less frequent. These non-perfusion data provide important prognostic and patient management information. Further, event rates in patients undergoing vasodilator MPI are higher than in those undergoing exercise MPI and even in those with normal images probably due to higher pretest risk. However, there are a number of non-perfusion variables that are obtained during vasodilator stress testing, which have prognostic relevance but their use has not been well emphasized. The purpose of this review is to summarize the prognostic values of these non-perfusion data obtained during vasodilator MPI.

The reproducibility and prognostic value of serial measurements of heart rate response to regadenoson during myocardial perfusion imaging

PURPOSE

The heart rate response (HRR, percentage change from baseline) to regadenoson during myocardial perfusion imaging (MPI) can provide incremental prognostic value in patients with known or suspected coronary artery disease. Our purpose was to evaluate the variability and prognostic value of HRR on serial measurements.

METHODS

We studied 648 consecutive patients (61 ± 11 years, 48 % with diabetes) who underwent two regadenoson MPI studies (16 ± 9 months between studies). HRR <30 % was defined as abnormal. All-cause mortality was determined by chart review and verified using the US Social Security Death Master File.

RESULTS

HRR was well correlated between the two studies (intraclass correlation coefficient 0.72, 95 % CI 0.67 - 0.76) with no systematic bias (mean difference 0.88 %, p = 0.2) or proportional bias (p = 0.5) by Bland-Altman analysis in all patients and in those with normal MPI on both studies. Of the 308 patients (48 %) with normal baseline HRR (HRR-1), 33 % had developed a blunted HRR on the second MPI study (HRR-2). Older age, male gender, end-stage renal disease, and abnormal baseline left ventricular ejection fraction were independent predictors of a new-onset abnormal HRR. During a mean follow-up of 2.4 ± 1.2 years, 55 patients (8.5 %) died. Patients with a blunted HRR-1 had increased mortality risk irrespective of their HRR-2 (p = 0.9, log-rank test). Among patients with normal HRR-1, a blunted HRR-2 was an independent predictor of all-cause mortality beyond clinical and traditional MPI data (hazard ratio 2.83, 95 % CI 1.14 - 7.03). Finally, patients with a normal HRR-1 and HRR-2 had the lowest event rate, while those with any abnormal HRR had an increased risk of death (hazard ratio 2.5, 95 % CI 1.2 - 5.4).

CONCLUSION

There was good correlation in the HRR to regadenoson on serial measurements without systematic or proportional biases. Patients with consistently normal HRR had the best prognosis.

Cardiac purinergic signalling in health and disease

This review is a historical account about purinergic signalling in the heart, for readers to see how ideas and understanding have changed as new experimental results were published. Initially, the focus is on the nervous control of the heart by ATP as a cotransmitter in sympathetic, parasympathetic, and sensory nerves, as well as in intracardiac neurons. Control of the heart by centers in the brain and vagal cardiovascular reflexes involving purines are also discussed. The actions of adenine nucleotides and nucleosides on cardiomyocytes, atrioventricular and sinoatrial nodes, cardiac fibroblasts, and coronary blood vessels are described. Cardiac release and degradation of ATP are also described. Finally, the involvement of purinergic signalling and its therapeutic potential in cardiac pathophysiology is reviewed, including acute and chronic heart failure, ischemia, infarction, arrhythmias, cardiomyopathy, syncope, hypertrophy, coronary artery disease, angina, diabetic cardiomyopathy, as well as heart transplantation and coronary bypass grafts.

Autonomic dysfunction independently predicts poor cardiovascular outcomes in asymptomatic individuals with type 2 diabetes in the DIAD study

Objective:

The primary aim of this secondary analysis was to determine whether cardiac autonomic neuropathy independently predicted adverse cardiac outcomes in asymptomatic individuals with type 2 diabetes. Additional aims include the determination of the correlation of standard autonomic testing measures and power spectral analysis of heart rate variability, and the association of diabetes-related and cardiac risk factors with cardiac autonomic neuropathy measures.

Methods:

Cardiac autonomic neuropathy was assessed at the study entry into the Detection of Ischemia in Asymptomatic Diabetics study, using autonomic heart rate and blood pressure testing, and power spectral analysis of heart rate variability. All participants were prospectively followed for the composite clinical outcome of cardiac death, acute coronary syndromes, heart failure, or coronary revascularization.

Results:

Over 5 years of follow-up, 94 of 1119 (8.4%) subjects developed symptomatic cardiac disease. In unadjusted bivariate analyses, abnormalities in several cardiac autonomic neuropathy tests, including lower Valsalva and Standing Heart Rate Ratios, higher resting Heart Rate, greater systolic blood pressure decrease on standing, and lower low-frequency power, were predictive of symptomatic disease. Independent predictors of poor cardiac outcome were a lower Valsalva Heart Rate Ratio, non-Black ethnicity, longer diabetes duration, higher glycated hemoglobin (HbA1c), insulin use, reported numbness in the extremities, higher pulse pressure, family history of coronary artery disease, and higher waist-to-hip ratio. Clinical factors independently associated with a lower Valsalva Heart Rate Ratio were insulin use, clinical proteinuria, higher pulse pressure, use of angiotensin-converting enzyme inhibitor and non-Black ethnicity.

Conclusion:

Cardiac autonomic neuropathy predicted adverse cardiac outcomes in asymptomatic type 2 diabetes without known cardiac disease. Clinical variables may help to identify patients who might have cardiac autonomic neuropathy and warrant consideration for autonomic testing.

Prognostic value of normal stress myocardial perfusion imaging in diabetic patients: a meta-analysis

BACKGROUND

The prognostic value of normal stress myocardial perfusion single-photon emission computed tomography (MPS) in patients with diabetes has only been evaluated in single-center studies of relatively limited sample size. We performed a meta-analysis of published studies, including diabetic patients with known or suspected coronary artery disease (CAD), to assess the predictive value for adverse cardiac ischemic events of normal stress MPS.

METHODS AND RESULTS

Studies published between January 1990 and December 2013 were identified by database search. We included studies using stress MPS to evaluate diabetic patients with known or suspected CAD and providing data on clinical outcomes of non-fatal myocardial infarction or cardiac death with a follow-up time ≥12 months. A total of 14 studies were finally included, recruiting 13,493 patients. The negative predictive value (NPV) for non-fatal myocardial infarction and cardiac death of normal MPS was 94.92% (95% confidence interval 93.67-96.05), during a weighted mean follow-up of 36.24 months, resulting in estimated event rate after a negative test equal to 5.08% (95% confidence interval 3.95-6.33). The corresponding annualized event rate after a negative test was 1.60% (95% confidence interval 1.21-2.04).

CONCLUSIONS

Stress MPS has a high NPV for adverse cardiac events in diabetic patients with known or suspected CAD leading to define a "relatively low-risk" patients category.

Prognostic Value of Normal Perfusion but Impaired Left Ventricular Function in the Diabetic Heart on Quantitative Gated Myocardial Perfusion SPECT

PURPOSE

This study aimed at identifying the predictive parameters on quantitative gated myocardial perfusion single-photon emission computed tomography (QG-SPECT) in diabetic patients with normal perfusion but impaired function.

METHODS

Among the 533 consecutive diabetic patients, 379 patients with normal perfusion on rest Tl-201/dipyridamole-stress Tc-99m sestamibi Gated SPECT were enrolled. Patients were grouped into those with normal post-stress left ventricular function (Group I) and those with impaired function (EF <50 or impaired regional wall motion, Group II). We investigated cardiac events and cause of death by chart review and telephone interview. Survival analysis and Cox proportional hazard model analysis were performed.

RESULTS

Between the Group I and II, cardiac events as well as chest pain symptoms, smoking, diabetic complications were significantly different (P < 0.05). On survival analysis, event free survival rate in Group II was significantly lower than in Group I (P = 0.016). In univariate Cox proportional hazard analysis on overall cardiac event, Group (II over I), diabetic nephropathy, summed motion score (SMS), summed systolic thickening score (STS), numbers of abnormal segmental wall motion and systolic thickening predicted more cardiac events (P < 0.05). Multivariate analysis showed that STS was the only independent predictor cardiac event.

CONCLUSION

The functional parameter, especially summed systolic thickening score on QG-SPECT had prognostic values, despite normal perfusion, in predicting cardiac events in diabetic patients, and QG-SPECT provides clinically useful risk stratification in diabetic patients with normal perfusion.

Cardiac autonomic neuropathy in patients with diabetes mellitus

Cardiac autonomic neuropathy (CAN) is an often overlooked and common complication of diabetes mellitus. CAN is associated with increased cardiovascular morbidity and mortality. The pathogenesis of CAN is complex and involves a cascade of pathways activated by hyperglycaemia resulting in neuronal ischaemia and cellular death. In addition, autoimmune and genetic factors are involved in the development of CAN. CAN might be subclinical for several years until the patient develops resting tachycardia, exercise intolerance, postural hypotension, cardiac dysfunction and diabetic cardiomyopathy. During its sub-clinical phase, heart rate variability that is influenced by the balance between parasympathetic and sympathetic tones can help in detecting CAN before the disease is symptomatic. Newer imaging techniques (such as scintigraphy) have allowed earlier detection of CAN in the pre-clinical phase and allowed better assessment of the sympathetic nervous system. One of the main difficulties in CAN research is the lack of a universally accepted definition of CAN; however, the Toronto Consensus Panel on Diabetic Neuropathy has recently issued guidance for the diagnosis and staging of CAN, and also proposed screening for CAN in patients with diabetes mellitus. A major challenge, however, is the lack of specific treatment to slow the progression or prevent the development of CAN. Lifestyle changes, improved metabolic control might prevent or slow the progression of CAN. Reversal will require combination of these treatments with new targeted therapeutic approaches. The aim of this article is to review the latest evidence regarding the epidemiology, pathogenesis, manifestations, diagnosis and treatment for CAN.

Fractional flow reserve versus angiography in guiding management to optimize outcomes in non-ST-elevation myocardial infarction (FAMOUS-NSTEMI): rationale and design of a randomized controlled clinical trial

BACKGROUND

In patients with acute non-ST-elevation myocardial infarction (NSTEMI), coronary arteriography is usually recommended; but visual interpretation of the angiogram is subjective. We hypothesized that functional assessment of coronary stenosis severity with a pressure-sensitive guide wire (fractional flow reserve [FFR]) would have additive diagnostic, clinical, and health economic utility as compared with angiography-guided standard care.

METHODS AND DESIGN

A prospective multicenter parallel-group 1:1 randomized controlled superiority trial in 350 NSTEMI patients with ≥1 coronary stenosis ≥30% severity (threshold for FFR measurement) will be conducted. Patients will be randomized immediately after coronary angiography to the FFR-guided group or angiography-guided group. All patients will then undergo FFR measurement in all vessels with a coronary stenosis ≥30% severity including culprit and nonculprit lesions. Fractional flow reserve will be disclosed to guide treatment in the FFR-guided group but not disclosed in the "angiography-guided" group. In the FFR-guided group, an FFR ≤0.80 will be an indication for revascularization by percutaneous coronary intervention or coronary artery bypass surgery, as appropriate. The primary outcome is the between-group difference in the proportion of patients allocated to medical management only compared with revascularization. Secondary outcomes include the occurrence of cardiac death or hospitalization for myocardial infarction or heart failure, quality of life, and health care costs. The minimum and average follow-up periods for the primary analysis are 6 and 18 months, respectively.

CONCLUSIONS

Our developmental clinical trial will address the feasibility of FFR measurement in NSTEMI and the influence of FFR disclosure on treatment decisions and health and economic outcomes.