Silent myocardial ischemia

Cardiac Autonomic Dysfunction and Risk of Silent Myocardial Infarction Among Adults With Type 2 Diabetes

Background There is a paucity of large-scale epidemiological studies on the link between cardiac autonomic neuropathy (CAN) and the risk of silent myocardial infarction (SMI) in type 2 diabetes. We evaluated the association between CAN and the risk of SMI in a large sample of adults with type 2 diabetes. Methods and Results Participants with type 2 diabetes from the ACCORD (Action to Control Cardiovascular Risk in Diabetes) study without atherosclerotic cardiovascular disease at baseline were included. CAN was ascertained using heart rate variability indices calculated from 10-s resting electrocardiograms. The heart rate variability indices included standard deviation of all normal-to-normal R-R intervals and root mean square of successive differences between normal-to-normal R-R intervals. CAN was defined as both the standard deviation of all normal-to-normal R-R intervals and root mean square of successive differences between normal-to-normal R-R intervals less than the fifth percentile of the general population. We used Cox proportional hazards regression to generate hazard ratios (HRs) for incident SMI in relation to CAN measures. Among 4842 participants (mean age, 62.5 years; 46.6% women; 60.2% White), there were 73 incident SMI cases over a median follow-up of 4.9 years (incidence rate 3.1 out of 1000 person-years [95% CI, 2.5-3.9]). After adjusting for confounders, low heart rate variability was associated with a higher risk of SMI (HR, 1.67 [95% CI, 1.02-2.72] and HR, 1.56 [95% CI, 0.94-2.58] for low standard deviation of all normal-to-normal R-R intervals and root mean square of successive differences between normal-to-normal R-R intervals, respectively). Participants with CAN had a 1.9-fold greater risk of SMI (HR, 1.91 [95% CI, 1.14-3.20]). Conclusions In a large cohort of adults with type 2 diabetes, CAN was significantly associated with an increased risk of incident SMI.

[Characteristics of chest pain in acute coronary syndromes seen in the cardiology department of Befelatanana (Madagascar)]

INTRODUCTION

Chest pain is one of the different elements of orientation for the diagnosis of acute coronary syndrome. Sometimes its clinical presentation is misleading. The objective of this study was to describe the characteristics of chest pain during an acute coronary syndrome in the cardiology department of the Joseph Raseta Befelatanana University Hospital Center, Antananarivo, Madagascar.

METHODS

We carried out a cross-sectional, descriptive study of 10 months from January 2019 to October 2019. All patients diagnosed with acute coronary syndrome during this period were included.

RESULTS

Sixty-five cases were included. A "typical chest pain" was only encountered in 7.7% of cases. Advanced age (p = 0.04) and sedentary lifestyle (p = 0.03) were associated with the occurrence of silent myocardial ischemia, and. hypertension with a prolonged duration (≥15 minutes) of chest pain (p = 0.03). Dyslipidemia was associated with atypical irradiation of chest pain (p = 0.003). Alcoholism had an impact on pain triggered by effort (p = 0.01) and relieved by rest (p = 0.04).

CONCLUSION

The current symptomatology of acute coronary syndrome is increasingly atypical. Knowledge of the factors that can influence the different characteristics of chest pain could serve as a benchmark in clinical practice in our population.

Large vessel occlusions requiring repeated mechanical thrombectomy caused by silent myocardial infarction in a young adult

OBJECTIVES

Silent myocardial ischemia, defined as objective evidence of myocardial ischemia without symptoms, is associated with ischemic stroke. Nevertheless, silent myocardial infarction is a rare cause of ischemic stroke, especially in young adults with no medical history.

MATERIALS AND METHODS

Herein, we report a young adult patient with acute ischemic stroke treated with repeated mechanical thrombectomy for recurrent large vessel occlusions caused by left ventricular thrombus following a silent myocardial infarction.

RESULTS

A 40-year-old man was transferred by ambulance to our hospital because of a generalized seizure. He was diagnosed with cerebral infarction and left middle cerebral artery occlusion. We performed intravenous thrombolysis and mechanical thrombectomy. Recanalization was achieved and his symptoms gradually improved. However, the day after treatment he developed bilateral cerebellar infarction and basilar artery occlusion. We performed a second mechanical thrombectomy and recanalization was achieved. Transthoracic echocardiography revealed a mobile left ventricular thrombus. Although he had no previous chest symptomatic episodes, cardiac examination confirmed myocardial infarction of unknown onset. He was diagnosed with acute ischemic stroke with large vessel occlusions caused by left ventricular thrombus following a silent myocardial infarction. Anticoagulation therapy reduced the amount of thrombus. At 1-year follow-up, he had not experienced any recurrences or symptoms.

CONCLUSIONS

Silent myocardial infarction should be considered a cause of ischemic stroke in young adults, even without any vascular risk factors. Recurrent large vessel occlusion may occur in patients with left ventricular thrombus, and repeated mechanical thrombectomy should be considered for treatment.

Dynamic detection and reversal of myocardial ischemia using an artificially intelligent bioelectronic medicine

Myocardial ischemia is spontaneous, frequently asymptomatic, and contributes to fatal cardiovascular consequences. Importantly, myocardial sensory networks cannot reliably detect and correct myocardial ischemia on their own. Here, we demonstrate an artificially intelligent and responsive bioelectronic medicine, where an artificial neural network (ANN) supplements myocardial sensory networks, enabling reliable detection and correction of myocardial ischemia. ANNs were first trained to decode spontaneous cardiovascular stress and myocardial ischemia with an overall accuracy of ~92%. ANN-controlled vagus nerve stimulation (VNS) significantly mitigated major physiological features of myocardial ischemia, including ST depression and arrhythmias. In contrast, open-loop VNS or ANN-controlled VNS following a caudal vagotomy essentially failed to reverse cardiovascular pathophysiology. Last, variants of ANNs were used to meet clinically relevant needs, including interpretable visualizations and unsupervised detection of emerging cardiovascular stress. Overall, these preclinical results suggest that ANNs can potentially supplement deficient myocardial sensory networks via an artificially intelligent bioelectronic medicine system.

Long-term in vivo operation of implanted cardiac nanogenerators in swine

Implantable nanogenerators (i-NG) provide power to cardiovascular implantable electronic devices (CIEDs) by harvesting biomechanical energy locally eliminating the need for batteries. However, its long-term operation and biological influences on the heart have not been tested. Here, we evaluate a soft and flexible i-NG system engineered for long-term in vivo cardiac implantation. It consisted of i-NG, leads, and receivers, and was implanted on the epicardium of swine hearts for 2 months. The i-NG system generated electric current throughout the testing period. Biocompatibility and biosafety were established based on normal blood and serum test results and no tissue reactions. Heart function was unchanged over the testing period as validated by normal electrocardiogram (ECG), transthoracic ultrasound, and invasive cardiac functional measures. This research demonstrates the safety, long term operation and therefore the feasibility of using i-NGs to power the next generation CIEDs.

Magnetic nanochains-based dynamic ELISA for rapid and ultrasensitive detection of acute myocardial infarction biomarkers

Acute myocardial infarction (AMI) is the leading cause of morbidity and mortality globally. The serum levels of a group of cardiac biomarkers have been regarded as important indicators in the routine diagnosis of AMI. The development of rapid, sensitive, and accurate detection methods of AMI biomarkers is urgently needed for the early diagnosis of AMI. Here, a dynamic and pseudo-homogeneous enzyme-linked immunosorbent assay (ELISA) was reported based on the combined use of bioconjugated magnetic nanochains (MNCs) and gold nanoparticles (AuNPs) probes. The capture antibodies-conjugated MNCs served as dynamic nano-mixers to facilitate liquid mixing and as homogeneously dispersed capturing agents to capture and separate specific targets. The AuNPs probes were prepared by co-immobilization of detection antibodies and horseradish peroxidase (HRP) for signals amplification. The design of bioconjugated MNCs and AuNPs probes significantly increased the assay kinetics and improves the assay sensitivity. This novel ELISA strategy realized accurate detection of a panel of AMI biomarkers within 35 min, leading to considerably improved sensitivities compared to that of conventional ELISA method.

Monte Carlo modeling of photon migration in realistic human thoracic tissues for noninvasive monitoring of cardiac hemodynamics

Noninvasive monitoring of cardiac hemodynamics remains challenging in cardiovascular medicine. The possibility of noninvasive optical monitoring of cardiac hemodynamics was theoretically investigated in this study. By utilizing the Monte Carlo simulation method for voxelized media (MCVM) and Visible Chinese Human dataset, we quantified and visualized the photon migration in human thoracic region. The light fluence distribution was showed to reach heart tissue (∼3 cm depth underbody surface) and 12% of the total fluence was absorbed by the myocardium. The proportion of spatial sensitivity distribution (SSD) in cardiac tissue to the total SSD reached 0.0195%. The portion of SSD increased following with cardiac diastole and diffuse reflectance deceased linearly with increasing cardiac volume. The optimal separation between the light source and detector was provided to be 3.5 to 4.0 cm for future development of noninvasive cardiac hemodynamics monitoring. A pilot experimental study was conducted to measure the diffuse reflectance light and fingertip photoplethysmography. These data suggest that the fluctuation period of near-infrared (NIR) diffuse reflectance was consistent with the cardiac cycle, while the fluctuation features of the NIR signal was not consistent with that of photoplethysmography. All results indicate the great potential of noninvasive optical monitoring of myocardial hemodynamics.

Effects of silent myocardial ischemia on functional fitness and physical independence in 60–79-year-old adults

Objective

Methods

Results

Conclusion

Occult obstructive coronary artery disease is associated with prolonged cardiac troponin elevation following strenuous exercise

Background

Sudden cardiac death among middle-aged recreational athletes is predominantly due to myocardial ischaemia. This study examined whether measuring cardiac troponin I and T (cTnI and cTnT) after strenuous exercise could identify occult obstructive coronary artery disease.

Design

Prospective observational study.

Methods

Subjects were recruited from 1002 asymptomatic recreational cyclists completing a 91-km mountain bike race (North Sea Race Endurance Exercise Study). No subject had known cardiovascular disease or took cardiovascular medication. Blood samples were collected within 24 h before and 3 h and 24 h after the race. Coronary computed tomography angiography was performed in 80 participants with the highest post-exercise cTnI and in 40 reference subjects with moderately elevated cTnI values.

Results

Study subjects ( N = 120) were 45 (36–52) years old and 74% were male. There were similar demographics in the High-cTnI group and the Reference group. The cTn concentrations were highest at 3 h post-race: cTnI, 224 (125–304) ng/L; cTnT, 89 (55–124) ng/L. Nine subjects had obstructive coronary artery disease on coronary computed tomography angiography, eight of whom were High-cTnI responders. Two subjects had myocardial bridging, both High-cTnI responders. Troponin concentrations at 24 h post-race were higher in subjects with obstructive coronary artery disease than in the rest of the cohort ( n = 109): cTnI, 151 (72–233) ng/L vs. 24 (19–82) ng/L, p = 0.005; cTnT, 39 (25–55) ng/L vs. 20 (14–31) ng/L, p = 0.002. The areas under the receiver operating characteristic curves for predicting obstructive coronary artery disease were 0.79, p = 0.005 (cTnI) and 0.82, p = 0.002 (cTnT).

Conclusion

In subjects with occult obstructive coronary artery disease there was a prolonged elevation of cTn following strenuous exercise.

Risk stratification for coronary artery disease in multi-ethnic populations: Are there broader considerations for cost efficiency?

Coronary artery disease (CAD) screening and diagnosis are core cardiac specialty services. From symptoms, autopsy correlations supported reductions in coronary blood flow and dynamic epicardial and microcirculatory coronaries artery disease as etiologies. While angina remains a clinical diagnosis, most cases require correlation with a diagnostic modality. At the onset of the evidence building process much research, now factored into guidelines were conducted among population and demographics that were homogenous and often prior to newer technologies being available. Today we see a more diverse multi-ethnic population whose characteristics and risks may not consistently match the populations from which guideline evidence is derived. While it would seem very unlikely that for the majority, scientific arguments against guidelines would differ, however from a translational perspective, there will be populations who differ and importantly there are cost-efficacy questions, e.g., the most suitable first-line tests or what parameters equate to an adequate test. This article reviews non-invasive diagnosis of CAD within the context of multi-ethnic patient populations.

Positive and Negative Affect Is Related to Experiencing Chest Pain During Exercise-Induced Myocardial Ischemia

OBJECTIVE

Silent myocardial ischemia is thought to be associated with worse cardiovascular outcomes due to a lack of perception of pain cues that initiate treatment seeking. Negative affect (NA) has been associated with increased pain reporting and positive affect (PA) with decreased pain reporting, but these psychological factors have not been examined within the context of myocardial ischemia. This study evaluated the associations between PA, NA, and chest pain reporting in patients with and without ischemia during exercise testing.

METHODS

A total of 246 patients referred for myocardial perfusion single-photon emission computed tomography exercise stress testing completed the positive and negative affect schedule-expanded version, a measure of PA and NA. Presence of chest pain and myocardial ischemia were evaluated using standardized protocols.

RESULTS

Logistic regression analyses revealed that for every 1-point increase in NA, there was a 13% higher chance for ischemic patients (odds ratio [OR] = 1.13; 95% confidence interval [CI] = 1.02 to 1.26) and an 11% higher chance in nonischemic patients (OR = 1.11; 95% CI = 1.03 to 1.19) to report chest pain. A significant interaction of PA and NA on chest pain reporting (β = 0.02; 95% CI = 0.002 to 0.031) was also observed; nonischemic patients with high NA and PA reported more chest pain (57%) versus patients with low NA and low PA (13%), with high NA and low PA (17%), and with high PA and low NA (7%).

CONCLUSIONS

Patients who experience higher NA are more likely to report experiencing chest pain. In patients without ischemia, high NA and PA was also associated with a higher likelihood of reporting chest pain. Results suggest that high levels of PA as well as NA may increase the experience and/or reporting of chest pain.

Risk factors for silent myocardial ischemia in patients with well-controlled essential hypertension

Silent myocardial ischemia (SMI) is frequently observed in patients with essential hypertension (EH). The major risk factor for SMI is uncontrolled blood pressure (BP), but SMI is also observed in patients with well-controlled BP. To evaluate the prevalence of SMI and the factors associated with SMI in EH patients with well-controlled BP. The medical records of 859 EH patients who underwent simultaneous 24-h ambulatory blood pressure monitoring (ABPM) and 24-h ambulatory electrocardiogram recording (AECG) were retrospectively evaluated. Each SMI episode was characterized by: (a) ST segment depression ≥0.5 mm; (b) duration of ST segment depression >60 s; and (c) reversibility of the ST segment depression. Overall 126 EH patients (14.7 %) had at least one episode of SMI. The SMI events were more frequent among patients with poorly controlled compared to those with well-controlled BP [86/479 (17.95 %) vs. 40/380 (10.52 %), p < 0.01]. Among EH patients with well-controlled BP, current and past smoking as well as the presence of an additional metabolic syndrome (MetS) constitutive element (obesity, impaired fasting glucose level or dyslipidemia) were significantly associated with the occurrence of SMI. In all EH patients with well-controlled BP and AECG evidence of SMI, there were one or more coronary artery stenotic lesions greater than 50 % found at coronary angiography. In EH patients who are current smokers, or have one or more additional components of a MetS there is markedly reduced benefit associated with good BP control with regard to the occurrence of myocardial ischemia: in this patient category, an AECG may help detect this condition.

Cardiovascular Testing in Asymptomatic Patients: Carotid Duplex, Cardiac Stress Testing, Screen for Peripheral Arterial Disease

Approximately one-third of deaths in the United States are from cardiovascular disease. Managing modifiable risk factors is paramount to reducing risk of heart disease and stroke. It is logical to try to identify patients with silent disease that may predispose them to significant morbidity and mortality. Unfortunately, it is unclear if routine screening for the presence of carotid stenosis, coronary artery disease, and peripheral arterial disease is beneficial. Many of these tests are expensive. This review explores the evidence behind screening tests, costs associated with the tests, and the implications of positive screening for each of the 3 listed conditions.

Mechanism of QSYQ on anti-apoptosis mediated by different subtypes of cyclooxygenase in AMI induced heart failure rats

Background

Qi-shen-yi-qi (QSYQ), one of the most well-known traditional Chinese medicine (TCM) formulas, has been shown to have cardioprotective effects in rats with heart failure (HF) induced by acute myocardial infarction (AMI). However, the mechanisms of its therapeutic effects remain unclear. In this study, we aim to explore the mechanisms of QSYQ in preventing left ventricular remodelling in rats with HF. The anti-apoptosis an anti-inflammation effects of QSYQ were investigated.

Methods

Sprague–Dawley (SD) rats were randomly divided into 4 groups: sham group, model group, QSYQ treatment group and aspirin group. Heart failure model was induced by ligation of left anterior descending (LAD) coronary artery. 28 days after surgery, hemodynamics were detected. Echocardiography was adopted to evaluate heart function. TUNEL assay was applied to assess myocardial apoptosis rates. Protein expressions of cyclooxygenase1 and 2 (COX1and COX2), Fas ligand (FasL), P53 and MDM2 were measured by western-blot. RT-PCR was applied to detect expressions of our subtype receptors of PGE2 (EP1, 2, 3, and 4).

Results

Ultrasonography showed that EF and FS values decreased significantly and abnormal hemodynamic alterations were observed in model group compared to sham group. These indications illustrated that HF models were successfully induced. Levels of inflammatory cytokines (TNF-α and IL-6) in myocardial tissue were up-regulated in the model group as compared to those in sham group. Western-blot analysis showed that cyclooxygenase 2, which is highly inducible by inflammatory cytokines, increased significantly. Moreover, RT-PCR showed that expressions of EP2 and EP4, which are the receptors of PGE2, were also up-regulated. Increased expressions of apoptotic pathway factors, including P53 and FasL, might be induced by the binding of PGE2 with EP2/4. MDM2, the inhibitor of P53, decreased in model group. TUNEL results manifested that apoptosis rates of myocardial cells increased in the model group. After treatment with QSYQ, expressions of inflammatory factors, including TNF-α, IL-6 and COX2, were reduced. Expressions of EP2 and EP4 receptors also decreased, suggesting that PGE2-mediated apoptosis was inhibited by QSYQ. MDM2 was up-regulated and P53 and FasL in the apoptotic pathway were down-regulated. Apoptosis rates in myocardial tissue in the QSYQ group decreased compared with those in the model group.

Conclusions

QSYQ exerts cardiac protective efficacy mainly through inhibiting the inflammatory response and down-regulating apoptosis. The anti-inflammatory and anti-apoptosis efficacies of QSYQ are probably achieved by inhibition of COXs-induced P53/FasL pathway. These findings provide experimental evidence for the beneficial effects of QSYQ in the clinical application for treating patients with HF.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0869-z) contains supplementary material, which is available to authorized users.

Clinical Significance of Late Enhancement and Regional Wall Remodeling Assessed by 3T Magnetic Resonance Imaging

BACKGROUND

Clinical follow-up studies comparing left ventricular (LV) function and late gadolinium enhancement (LGE) by high-field 3T cardiac magnetic resonance (CMR) are of general interest due to the increased use of 3T scanners. In this study, the occurrence of LGE and LV regional wall remodeling (RWR) was assessed by 3T CMR in patients undergoing coronary angiography for suspected stable coronary artery disease (CAD).

MATERIALS AND METHODS

Analysis of myocardial viability by LGE was performed at the segmental level. LVRWR was identified by a significant reduction (≥50%) of the wall thickness. Major adverse cardiovascular events (MACE) were registered during a median follow-up time of 58 (45-62) months.

RESULTS

Of the 87 patients (59 ± 9 years; 13 women) enrolled, nonviable myocardium was detected in 35 (40%) and significant CAD in 69 (79%). Nonviable myocardium was correlated to angiographic significant stenosis or occlusion. LVRWR was significantly related to a higher number of nonviable segments compared to those without LVRWR: ie, 6.0 ± 3.2 segments versus 2.6 ± 1.3; P < 0.001. In the nonviable group, LVEF was significantly reduced (P < 0.001) compared to the viable group: ie, 50 ± 16% versus 61 ± 8%, and LVEF was significantly correlated to the number of nonviable segments (r = -0.66, P < 0.001). The number of nonviable segments by LGE was significantly associated with MACE by an odds ratio of 1.25 (95% CI, 1.05-1.49; P = 0.013).

CONCLUSION

The presence of nonviable myocardium as detected by LGE at 3T CMR is associated with angiographically significant CAD, and is associated with the development of LVRWR and reduced LVEF. Assessing the extent of nonviable myocardium by both LGE and LVRWR at the segmental level may therefore contribute to individualized risk stratification and treatment strategies.

Impact of non-chest pain complaint as a presenting symptom on door-to-balloon time and clinical outcomes in patients with acute ST-elevation myocardial infarction

Many patients with ST-elevation myocardial infarctions (STEMIs) have non-chest pain complaints and are given low priority during triage. This prospective, multicenter, observational, registry-based study investigated the impact of non-chest pain complaints on door-to-balloon (DTB) time and clinical outcomes. Patients with STEMI who had undergone primary percutaneous coronary intervention were compared with respect to the presence of chest pain or non-chest pain complaints as presenting symptoms. To eliminate biased estimates, a propensity score model was built, and 2 cohorts of 1:1 matched patients were obtained. Propensity matching identified 2 cohorts of 976 patients each. After comparing patients with chest pain and those with non-chest pain complaints, significant delays in the median DTB time were noted (74 vs 84 minutes, respectively; p <0.001). Non-chest pain complaints were independent predictors of DTB time in the multivariate linear regression models. In-hospital mortality (adjusted hazard ratio [HR] 1.402, 95% confidence interval [CI] 0.727 to 2.705, p = 0.313), all-cause mortality (adjusted HR 1.175, 95% CI 0.453 to 3.853, p = 0.642), and major adverse cardiac events at follow-up (adjusted HR 0.139, 95% CI 0.876 to 1.48, p = 0.331) did not differ between the 2 groups of patients. In conclusion, short- and long-term clinical outcomes in patients with STEMI with non-chest pain complaints do not differ from those of patients with chest pain as the presenting symptom, despite having delayed diagnosis and reperfusion.

Ultrasound molecular imaging of transient acute myocardial ischemia with a clinically translatable P- and E-selectin targeted contrast agent: correlation with the expression of selectins

OBJECTIVE

The diagnosis of acute coronary syndrome remains challenging especially in patients without clear symptoms or electrocardiographic and/or biomarker features. A hallmark of ischemia/reperfusion is activation of endothelial cells leading to altered expression of molecular markers, including selectins. In this context, we aimed to validate the value of ultrasound molecular imaging for detecting transient myocardial ischemia by using a clinically translatable dual P- and E-selectin-targeted ultrasound contrast agent (UCA) and microbubble (MB(selectin)).

MATERIAL AND METHODS

Transient (20 minutes) myocardial ischemia of rat heart was produced by ligation of the left anterior descending coronary artery ligation followed by 2-, 5-, or 24-hour reperfusion. Imaging of the transient ischemic event was achieved by the use of MB(selectin). Performance of this clinically translatable targeted UCA was compared with that of antibody-targeted streptavidin MBs. Finally, immunohistochemistry staining of rat myocardial ischemic tissue was performed to assess expression of selectins accessible to targeted UCA.

RESULTS

In rats subjected to myocardial ischemia (20 minutes) followed by reperfusion (2 hours), injection of MB(selectin) produced high late phase (ie, 10-minute postinjection) ultrasound molecular imaging enhancement in the myocardium, which colocalized with the ischemic area. Late phase enhancement persisted 5 and 24 hours after reperfusion. Similarly, the use of MBP and MBE, comprising antibodies specific for P- and E-selectin, respectively, showed high late-phase enhancement within the ischemic area compared with remote myocardial tissue. Two and 5 hours after ischemia has resolved, a persistent expression of these 2 selectins was detected. After 24 hours of reperfusion, only MBE produced late phase enhancement within the ischemic myocardium. Immunohistochemical findings revealed that both P- and E-selectin were expressed and accessible on the surface of the activated endothelium 2 and 5 hours after the acute ischemic event, whereas only E-selectin remained accessible after 24 hours.

CONCLUSIONS

Ultrasound molecular imaging of transient myocardial ischemia using dual selectin-targeted UCA is able to monitor the time course of expression of selectins after resolution of the ischemic event, paving the way for a large clinical diagnostic window.

Integrated proteomic and metabolomic analysis reveals the NADH-mediated TCA cycle and energy metabolism disorders based on a new model of chronic progressive heart failure

BACKGROUND

Despite major advances in the treatment of heart failure (HF), it remains the major cause of mortality and morbidity worldwide. Experimental models of HF typically utilize acute myocardial infarction. However, the majority of clinical HFs occur gradually by a chronic progressive mechanism. Thus, more relevant models are required to aid identification, quantification, and characterization of HF, and its underlying mechanisms.

METHODS AND FINDINGS

We developed a model of progressive chronic heart failure (CHF) in the mini-swine by placement of an ameroid constrictor on the left anterior descending coronary artery (LAD). This model demonstrated a steady decline in the cardiac function from 8 to 12 weeks, with a 50% reduction in the ejection fraction. Further, the proteomic, metabolomic and bioinformatic analyses of ischemic tissue and plasma revealed a significant alteration of the mitochondrial respiratory chain mediated by nicotinamide adenine dinucleotide (NADH), which resulted in down-regulation of malate dehydrogenase (MDH) and insufficient energy supply to support cardiac contractility and relaxation. Furthermore, significant changes in apolipoprotein A-I, low density lipoprotein (LDL), and very LDL (VLDL) in plasma indicated that lipid metabolism disorders occurred in mini-swines with myocardial ischemia via glycerolipid metabolism.

CONCLUSIONS

We describe a stable and easily reproducible CHF model using an ameroid constrictor placed on the LAD. We found that the NADH-mediated tricarboxylic acid cycle and energy metabolism disorders are key pathophysiological mechanisms underlying CHF. These data will provide potential biomarkers for monitoring the therapeutic intervention of CHF.

Small changes in troponin T levels are common in patients with non-ST-segment elevation myocardial infarction and are linked to higher mortality

OBJECTIVES

The purpose of this study was to examine the extent of change in troponin T levels in patients with non-ST-segment elevation myocardial infarction (NSTEMI).

BACKGROUND

Changes in cardiac troponin T (cTnT) levels are required for the diagnosis of NSTEMI, according to the new universal definition of acute myocardial infarction. A relative change of 20% to 230% and an absolute change of 7 to 9 ng/l have been suggested as cutoff points.

METHODS

In a clinical setting, where a change in cTnT was not mandatory for the diagnosis of NSTEMI, serial samples of cTnT were measured with a high-sensitivity cTnT (hs-cTnT) assay, and 37 clinical parameters were evaluated in 1,178 patients with a final diagnosis of NSTEMI presenting <24 h after symptom onset.

RESULTS

After 6 h of observation, the relative change in the hs-cTnT level remained <20% in 26% and the absolute change <9 ng/l in 12% of the NSTEMI patients. A relative hs-cTnT change <20% was linked to higher long-term mortality across quartiles (p = 0.002) and in multivariate analyses (hazard ratio: 1.61 [95% confidence interval: 1.17 to 2.21], p = 0.004), whereas 30-day mortality was similar across quartiles of relative hs-cTnT change.

CONCLUSIONS

Because stable hs-TnT levels are common in patients with a clinical diagnosis of NSTEMI in our hospital, a small hs-cTnT change may not be useful to exclude NSTEMI, particularly as these patients show both short-term and long-term mortality at least as high as patients with large changes in hs-cTnT.

Primary headache and silent myocardial ischemia in patients with coronary artery disease

OBJECTIVE

The mechanisms by which migraine is linked to ischemic vascular disease remain uncertain and are likely to be complex. The aim of this study was to investigate the correlation between silent myocardial ischemia (SMI) and a history of documented primary headache in a large population of patients with exercise-induced myocardial ischemia.

METHODS

The study involved 1,427 consecutive patients (918 symptomatic and 509 asymptomatic patients) with exercise-induced myocardial ischemia and documented coronary artery disease (CAD).

RESULTS

Patients with anginal symptoms during exercise-induced myocardial ischemia had a significantly higher prevalence of primary headache than those without (41 vs. 30%, p < 0.001). Patients with angina pectoris in daily life also had greater prevalence of primary headache than those without anginal symptoms (37 vs. 20%; p < 0.0001). Symptomatic patients during percutaneous transluminal coronary angiography or myocardial infarction had a greater prevalence of primary headache than asymptomatic patients (p < 0.001 and p = 0.005, respectively).

CONCLUSIONS

Our data suggest that a history of headache in CAD population is correlated to a high probability of anginal symptoms and a decreased probability of SMI. The anamnestic absence of headache requires a close monitoring for patients with risk factors for CAD, because this population seems to have a lower susceptibility to pain and the risk of developing SMI might be increased.

Psychological and physiological predictors of angina during exercise-induced ischemia in patients with coronary artery disease

OBJECTIVE

This study compares sensory-biological, cognitive-emotional, and cognitive-interpretational factors in predicting angina on an exercise treadmill test (ETT).

METHODS

A total of 163 patients with ETT-induced ischemia and coronary artery disease in the National Heart, Lung, and Blood Institute Psychophysiological Investigations of Myocardial Ischemia study were given an ETT, during which 79 patients reported angina. We assessed the following as potential predictors of self-reported anginal pain: sensory-biological factors (β-endorphin reactivity, hot pain threshold, and maximal ST-segment depression), cognitive-emotional factors (negative affect and symptom perception), and cognitive-interpretational factors (self-reported history of exercise-induced angina). Models were covariate adjusted with predictors examined individually and as part of component blocks.

RESULTS

Logistic regression revealed that history of angina (odds ratio [OR] = 17.41, 95% confidence interval = 7.16-42.34) and negative affect (OR = 1.65, 95% confidence interval = 1.17-2.34), but not maximal ST-segment depression, hot pain threshold, β-endorphin reactivity, or symptom perception, were significant predictors of angina on the ETT. The sensory-biological block was not significantly predictive of anginal pain (χ(2)block = 5.15, p = .741). However, the cognitive-emotional block (χ(2)block = 11.19, p = .004) and history of angina (cognitive-interpretation; χ(2)block = 54.87, p < .001) were predictive of ETT angina. A model including all variables revealed that only history of angina was predictive of ETT pain (OR = 16.39, p < .001), although negative affect approached significance (OR = 1.45, p = .07).

CONCLUSIONS

In patients with ischemia, cognitive-emotional and cognitive-interpretational factors are important predictors of exercise angina.

Painless myocardial ischemia is associated with mortality in patients with chronic kidney disease

BACKGROUND

Painless myocardial ischemia (PMI) is associated with poor outcomes in the general population. We hypothesized that the presence of PMI is inversely related to the level of kidney function and is associated with impaired survival in chronic kidney disease (CKD).

METHODS

A total of 356 patients who underwent percutaneous coronary intervention were assessed for PMI, which was defined as the absence of chest pain in response to balloon dilation of the affected vessel. Cox proportional hazards analysis was used to calculate 10-year all-cause mortality.

RESULTS

There was an increase in PMI occurrence by strata of estimated glomerular filtration rate (eGFR), whereby PMI was present in only 20.6% of individuals with eGFR ≥ 90 ml/min/1.73 m(2), but was found in 50.0% of individuals with eGFR <30 ml/min/1.73 m(2) (p = 0.004 for trend). Classification of individuals as having either CKD or PMI showed significant differences in adjusted mortality between groups (p < 0.001 for trend), with individuals having both CKD and PMI demonstrating the highest 10-year mortality. Compared to individuals with neither CKD nor PMI, individuals with CKD and no PMI had a hazard ratio (HR) for mortality of 1.64 (95% CI: 1.03-2.63, p = 0.038), while individuals with both PMI and CKD had an HR of 2.08 (1.30-3.33, p = 0.002).

CONCLUSION

PMI is common in the CKD population, is inversely related to the level of eGFR, and confers a substantially increased risk in CKD. These findings may partially explain the high mortality traditionally attributed to cardiovascular disease in CKD patients.

Comparison of chronic kidney disease and risk for presenting with painless versus nonpainless acute myocardial infarction

Chronic kidney disease increases the risk for developing ischemic heart disease, but it has not been well known whether it also affects the manifestation of painless acute myocardial infarction (AMI), which has important clinical implications. The aim of this study was to identify whether chronic kidney disease is associated with the presentation of painless AMI. A total of 2,656 consecutively hospitalized patients with AMI from January 2008 to February 2012 were enrolled. Estimated glomerular filtration rate (eGFR) was calculated using calibrated serum creatinine and the abbreviated Modification of Diet in Renal Disease (MDRD) equation. Patient clinical characteristics, angiographic findings, and the use of medications were reviewed. Multivariate logistic regression analysis was used to examine the association of reduced eGFR and presentation with painless AMI. A total of 2,176 adults with painful AMI and 480 adults with painless AMI were studied, and baseline eGFR was calculated. Mean eGFR was lower in subjects with painless AMI compared to those with painful AMI. Compared to an eGFR >90 ml/min/1.73 m(2), a strong, graded, independent association was observed between reduced eGFR and presentation with painless AMI, with adjusted odds ratios of 1.65 (95% confidence interval 1.16 to 2.36) for an eGFR of 60 to 89 ml/min/1.73 m(2), 2.92 (95% confidence interval 1.89 to 4.52) for an eGFR of 45 to 59 ml/min/1.73 m(2), and 3.44 (95% confidence interval 2.20 to 5.38) for an eGFR <45 ml/min/1.73 m(2). In conclusion, lower eGFR was a strong, independent predictor of presentation with painless AMI versus painful AMI.

Impaired fasting glucose in combination with silent myocardial ischaemia is associated with poor prognosis in healthy individuals

AIM

As both impaired fasting glucose and silent myocardial ischaemia are risk factors for cardiovascular disease and death, we hypothesized that these risk factors in combination would identify those subjects at the highest risk of adverse events.

METHODS

Healthy individuals without diabetes (n=596, 55-75 years) were examined for silent myocardial infarction (≥ 1 mm ST-interval during ≥ 1 min) by ambulant 48-h continuous electrocardiogram monitoring and impaired fasting glucose (fasting plasma glucose 5.6-6.9 mmol/l).

RESULTS

After 6.3 years, 77 subjects met the endpoint of myocardial infarction and/or death. The prevalence of silent myocardial ischaemia at inclusion was 12.3% in subjects with impaired fasting glucose and 11.7% in subjects with normal fasting glucose, P=0.69. Subjects with impaired fasting glucose/silent myocardial ischaemia more often met the endpoint (36%) than subjects with impaired fasting glucose/no silent myocardial ischaemia (15%), subjects with normal fasting glucose/silent myocardial ischaemia (12%), and subjects with normal fasting glucose/no silent myocardial ischaemia (10%), respectively, (P<0.001). In a Cox model including these four study groups of interest, gender, age, smoking habits, blood pressure and total cholesterol, only subjects with impaired fasting glucose/silent myocardial ischaemia exhibited an increased risk of death or myocardial infarction (hazard ratio 2.5, P=0.016).

CONCLUSION

The combination of impaired fasting glucose and silent myocardial ischaemia was associated with the poorest prognosis in middle-aged and older subjects without previously known glucose metabolic aberration and heart disease.

Myocardial ischemia, reperfusion, and infarction in chronically instrumented, intact, conscious, and unrestrained mice

In the United States alone, the National Heart, Lung, and Blood Institute (NHLBI) has invested several hundred million dollars in pursuit of myocardial infarct-sparing therapies. However, due largely to methodological limitations, this investment has not produced any notable clinical application or cardioprotective therapy. Among the major methodological limitations is the reliance on animal models that do not mimic the clinical situation. In this context, the limited use of conscious animal models is of major concern. In fact, whenever possible, studies of cardiovascular physiology and pathophysiology should be conducted in conscious, complex models to avoid the complications associated with the use of anesthesia and surgical trauma. The mouse has significant advantages over other experimental models for the investigation of infarct-sparing therapies. The mouse is inexpensive, has a high throughput, and presents the ability of one to create genetically modified models. However, successful infarct-sparing therapies in anesthetized mice or isolated mouse hearts may not be successful in more complex models, including conscious mice. Accordingly, a conscious mouse model of myocardial ischemia and reperfusion has the potential to be of major importance for advancing the concepts and methods that drive the development of infarct-sparing therapies. Therefore, we describe, for the first time, the use of an intact, conscious, and unrestrained mouse model of myocardial ischemia-reperfusion and infarction. The conscious mouse model permits occlusion and reperfusion of the left anterior descending coronary artery in an intact, complex model free of the confounding influences of anesthetics and surgical trauma. This methodology may be adopted for advancing the concepts and ideas that drive cardiovascular research.

Silent ischemia: clinical relevance

Myocardial ischemia can occur without overt symptoms. In fact, asymptomatic (or silent) ST-segment depression during ambulatory electrocardiogram monitoring occurs more often than symptomatic ST-segment depression in patients with coronary artery disease. Initial studies documented that silent ischemia provided independent prediction of adverse outcomes in patients with known and unknown coronary artery disease. The ACIP (Asymptomatic Cardiac Ischemia Pilot Study) enrolled patients in the 1990s and found that revascularization was better than medical therapy in reducing silent ischemic episodes and possibly cardiovascular (CV) events. However, the more recent COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial found similar CV event rates between patients treated with optimal medical therapy alone and those treated with optimal medical therapy plus percutaneous revascularization. Therefore, in the current era, medical therapy appears to be as effective as revascularization in suppressing symptomatic ischemia and preventing CV events. COURAGE was not designed to evaluate changes in the frequency of silent ischemia. Therefore, silent ischemia may persist despite current-era treatment and might still identify patients with increased risk of CV events. Also, silent ischemia is likely to occur frequently in heart transplant patients with denervated hearts and coronary allograft vasculopathy, and future study aimed at improving the management of silent ischemia in this population is warranted. Additionally, future research is warranted to study the effect of newer medical therapies such as ranolazine or selected use of revascularization (for example, guided by fractional flow reserve) in those patients with persistent silent ischemia despite optimal current-era medical therapy.

Comparison of outcomes of patients with painless versus painful ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention

There are few data available on the prognosis of painless ST-segment elevation myocardial infarction (STEMI). The aim of this study was to determine the incidence, clinical characteristics, and outcomes of painless STEMI. We analyzed the Korea Acute Myocardial Infarction Registry (KAMIR) study, which enrolled 7,288 patients with STEMI (61.8 ± 12.8 years old, 74% men; painless STEMI group, n = 763; painful STEMI group, n = 6,525). End points were in-hospital mortality and 1-year major adverse cardiac events (MACEs). Patients with painless STEMI were older and more likely to be women, nonsmokers, diabetic, and normolipidemic and to have a higher Killip class. The painless group had more in-hospital deaths (5.9% vs 3.6%, p = 0.026) and 1-year MACEs (26% vs 19%, p = 0.002). In Cox proportional hazards analysis, hypotension (hazard ratio [HR] 4.40, 95% confidence interval [CI] 1.41 to 13.78, p = 0.011), low left ventricular ejection fraction (HR 3.12, 95% CI 1.21 to 8.07, p = 0.019), and a high Killip class (HR 3.48, 95% CI 1.19 to 10.22, p = 0.023) were independent predictors of 1-year MACEs in patients with painless STEMI. In conclusion, painless STEMI was associated with more adverse outcomes than painful STEMI and late detection may have contributed significantly to total ischemic burden. These results warrant more investigations for methodologic development in the diagnosis of silent ischemia and painless STEMI.

Protein immobilization on 3C-SiC (100) as a substrate for detecting the onset of acute myocardial infarction (AMI)

Silicon Carbide (SiC), has been shown to be a bio- and hema-compatible substrate that could potentially be used in biosensor applications. The development of a viable biorecognition interface using SiC as the substrate material for bio-detection is described. Surface modification with 3-aminopropyltriethoxysilane (APTES) and immobilization via covalent conjugation of antimyoglobin (anti-Myo) on the modified surfaces is achieved, which are initial steps for immunosensing based devices. Successful formation of APTES layers and antibody immobilization were identified with surface water contact angle (SWCA), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM).

Targeting ASIC3 for pain, anxiety, and insulin resistance

The acid-sensing ion channel 3 (ASIC3) is a pH sensor that responds to mild extracellular acidification and is predominantly expressed in nociceptors. There is much interest in targeting ASIC3 to relieve pain associated with tissue acidosis, and selective drugs targeting ASIC3 have been used to relieve acid-evoked pain in animal models and human studies. There is accumulating evidence that ASIC3 is widely expressed in many neuronal and non-neuronal cells, such as neurons in the brain and adipose cells, albeit to a lesser extent than in nociceptors. Asic3-knockout mice have reduced anxiety levels and enhanced insulin sensitivity, suggesting that antagonizing ASIC3 has additional benefits. This view is tempered by recent studies suggesting that Asic3-knockout mice may experience cardiovascular disturbances. Due to the development of ASIC3 antagonists as analgesics, we review here the additional benefits, safety, risks, and strategy associated with antagonizing ASIC3 function.

Brain responses to cardiac electrical stimulation: a new EEG method for evaluating cardiac sensation

Although cardiac sensation, such as palpitation or chest pain, is common and is sometimes a malignant sign of heart diseases, the mechanism by which the human brain responds to afferent signals from the heart remains unclear. In this study, we investigated whether electrical stimulation of the heart provokes brain responses in humans. We examined 15 patients (age: 65.4 ± 3.1 years old, 11 males and 4 females) implanted with either a cardiac pacemaker or cardiac resynchronization therapy (CRT) device. Electroencephalogram (EEG) was simultaneously recorded from the vertex during right ventricular pacing at 70-100 beats/min at baseline (1.5 V) and intense (6-8 V) stimulation sessions. We evaluated brain responses to cardiac electrical stimulation by measuring cerebral potentials that were obtained by subtracting the average of 100 EEG waves triggered by cardiac pacing during baseline stimulation from those during the intense stimulation. Intense stimulation of the cardiac pacemaker or CRT device reproducibly induced cardiac sensation in 6 out of the 15 patients; namely, the remaining 9 patients showed no reproducible response. Brain responses were evident by averaging cerebral potentials from all of the 15 patients and those from 6 patients with reproducible cardiac sensation. To the best our knowledge, this is the first report that demonstrates the brain responses to cardiac electrical stimulation in humans. This new method should be useful for examining pathophysiology of cardiac diseases with pathological cardiac sensation, including cardiac anxiety and silent myocardial ischemia.

Antiatherogenic and Anti-Ischemic Properties of Traditional Chinese Medicine Xinkeshu via Endothelial Protecting Function

Including herbal medicine, complementary and alternative medicine (CAM) is popular worldwide. The traditional Chinese medicine xinkeshu has been widely used to treat coronary heart disease in China. This study was designed to investigate the protective effect and probable mechanism of xinkeshu tablet to atherosclerotic myocardial ischemia rabbit. Rabbits were divided into four groups (n = 12 each) and fed with different diet for 12 weeks: Control (standard diet), Model (high-cholesterol diet), XKS (high-cholesterol diet with 184.8 mg/kg/d xinkeshu), and Atorvastatin (high-cholesterol diet with 5.0 mg/kg/d atorvastatin). Plasma lipoprotein, ECG, endothelium-dependent vessel relaxation, histomorphological study, and expressions of eNOS and VCAM-1 on coronary arteries were assessed. The findings showed that, similar to atorvastatin, xinkeshu presented significant effects on rescuing endothelium-dependent vessel relaxation, inhibiting atherosclerotic progress, preventing myocardial ischemia, and changing eNOS and VCAM-1 expression. However, xinkeshu showed no lipoprotein lowering effect in hypercholesterolemia rabbits. The results of the present study indicated that xinkeshu exerted potent antiatherogenic and anti-ischemic properties on atherosclerotic myocardial ischemia rabbit. An endothelial protecting effect may be involved in the mechanism other than antihyperlipidemic effect.

Clinical presentation of acute coronary syndrome in HIV infected adults: a retrospective analysis of a prospectively collected cohort

OBJECTIVES

To compare clinical presentation and short-term prognosis of acute coronary syndrome (ACS) in HIV-infected and uninfected adults.

DESIGN

Retrospective analysis of a prospectively collected cohort.

METHODS

HIV-infected patients with myocardial infarction or unstable angina were identified by clinical history and specific characteristics of HIV infection were consecutively registered. Surviving patients were followed for at least one month after discharge. Risk factors for cardiovascular disease, clinical symptoms at admission, type of ACS, delivery of care, and factors associated with prognosis were compared between HIV-infected and uninfected adults.

RESULTS

Among 627 patients included, 44 (7%) were HIV-infected patients. HIV-infected patients were younger, more frequently men, and had higher prevalence of cardiovascular risk factors than uninfected patients. HIV-infected patients persisted frequently with less pain at Emergency Department (ED) (34% vs 82%, P<0.001) and complained of dyspnea (2% vs 15%, P<0.05) persisted in respect to HIV-uninfected patients. ST-elevation myocardial infarction was the most frequent ACS in HIV-infected patients (59% vs 24%) whereas non-ST-elevation myocardial infarction (23% vs 38%) and unstable angina (18% vs 38%) were the predominant ones in uninfected patients (P<0.001). Catheterism was performed more commonly in HIV-infected patients (75% vs 62%, P<0.01) and similarly admitted in the coronary care unit (38% vs 41%, P=0.81). The evolution was similar in both groups. When HIV-infected patients were matched by age and sex with a subgroup of 88 HIV-uninfected patients, most of the differences disappeared.

CONCLUSIONS

HIV-infected adults presenting with ACS are younger and have fewer symptoms than uninfected. Despite having a more established disease, short-term prognosis is similar.

Frequency and characteristics of myocardial ischemia recorded during stress echocardiography in patients with high coronary risk

BACKGROUND/AIM

Ischemic heart disease is the major cause of morbidity and mortality in the world as well as in our country. Ischemic heart disease has the multifactorial origin and the presence of several risk factors increases the risk of myocardial ischemia. The aim of the study was to evaluate the frequency and characteristics of myocardial ischemia in asymptomatic subjects with two or more risk factors for coronary artery disease during stress echocardiography.

METHODS

In 240 high risk asymptomatic subjects (an absolute risk of fatal cardiovascular disease of more than 5%, according to the Systemic Coronary Risk Evaluation Chart), the exercise stress echocardiography test was performed. The criterion for myocardial ischemia was the appearance of transient segmental wall motion abnormality (WMA). The wall motion score index was calculated before and after the exercise stress echocardiography.

RESULTS

During exercise stress echocardiography, in 36 (15%) subjects WMA occurred. Out of 36 subjects with myocardial ischemia, in 10 (27.8%) subjects WMA and ST segment depression were accompanied with the first occurrence of chest pain (the subgroup with symptomatic myocardial ischemia), in 20 (55.6%) subjects WMA and ST segment depression were detected and in 6 (16.6%) subjects only WMA occurred (the subgroup with silent myocardial ischemia). There were no significant differences between the subgroups with symptomatic and silent myocardial ischemia with regard to exercise tolerance, heart rate at the onset of WMA, and time to the onset of WMA, but the wall motion score index was significantly higher in the subjects with symptomatic myocardial ischemia (p < 0.01). In all the individuals with symptomatic myocardial ischemia, significant stenosis of the coronary arteries was found by coronary angiography. Out of 26 subjects with asymptomatic myocardial ischemia, coronary angiography was performed in 18 and significant stenosis of the coronary arteries was diagnosed in all of them. The number and grade of coronary stenosis in subjects with symptomatic and silent myocardial ischemia were similar.

CONCLUSION

The obtained results presented the incidence of myocardial ischemia in 15% of asymptomatic subjects with high coronary risk during stress echocardiography. Silent myocardial ischemia was markedly more frequent than symptomatic one, but in the subjects with symptomatic ischemia, the wall motion score index was significantly higher.

Complications in postbariatric body contouring: strategies for assessment and prevention

Massive weight loss patients present specific challenges to the plastic surgeon. Review of these issues may be valuable for the surgeon who does not specialize in this area. Obtaining excellent results involves a comprehensive perioperative approach, beginning with proper patient selection and appropriate expectations. Operative considerations such as hypothermia prevention and thromboembolic prophylaxis can play a role in improving outcomes and reducing morbidity. Appropriately focused postoperative care completes the surgical plan, leading to satisfying results for both patient and surgeon.

Cardiovascular risk evaluation and prevalence of silent myocardial ischemia in subjects with asymptomatic carotid artery disease

Introduction:

Silent ischemia is an asymptomatic form of myocardial ischemia, not associated with angina or anginal equivalent symptoms, which can be demonstrated by changes in ECG, left ventricular function, myocardial perfusion, and metabolism. The aim of this study was to evaluate the prevalence of silent myocardial ischemia in a group of patients with asymptomatic carotid stenosis.

Methods:

A total of 37 patients with asymptomatic carotid plaques, without chest pain or dyspnea, was investigated. These patients were studied for age, sex, hypertension, diabetes, dyslipidemia, smoking, and family history of cardiac disease, and underwent technetium-99 m sestamibi myocardial stress-rest scintigraphy and echo-color Doppler examination of carotid arteries.

Results:

A statistically significant relationship (P = 0.023) was shown between positive responders and negative responders to scintigraphy test when both were tested for degree of stenosis. This relationship is surprising in view of the small number of patients in our sample. Individuals who had a positive scintigraphy test had a mean stenosis degree of 35% ± 7% compared with a mean of 44% ± 13% for those with a negative test. Specificity of our detection was 81%, with positive and negative predictive values of 60% and 63%, respectively.

Conclusion:

The present study confirms that carotid atherosclerosis is associated with coronary atherosclerosis and highlights the importance of screening for ischemic heart disease in patients with asymptomatic carotid plaques, considering eventually plaque morphology (symmetry, composition, eccentricity or concentricity of the plaque, etc) for patient stratification.

Cardiac magnetic resonance imaging: choice of the year: which imaging modality is best for evaluation of myocardial ischemia? (MRI-side)

The increasing variety of available cardiac imaging techniques have made the investigation of coronary artery disease more complex. On the one hand, nuclear cardiology or myocardial perfusion imaging (MPI) allows accurate and reliable quantitative measurement of myocardial blood flow. On the other hand, a newer technique, cardiac magnetic resonance imaging (CMR) is an attractive alternative for achieving similar purposes without exposing patients to radiation hazards. With a higher spatial resolution, CMR is more sensitive for detecting subendocardial ischemia; small myocardial infarction and/or fibrosis, which cannot be achieved in a nuclear study. Nuclear MPI has dominated clinical practice over the past 3 decades on the basis of an extensive amount of research. More upcoming research on CMR would warrant more evidence-based data of its value for disease diagnosis, prognosis and risk stratification and incorporating it into the clinical diagnostic and management algorithm.

Strain measurements during adenosine triphosphate infusion before and after percutaneous coronary intervention

BACKGROUND

In regional myocardial ischemia, contractile delay develops, which can be assessed by measuring time to peak strain (TPS) on tissue Doppler imaging. The aims of the present study were to clarify the usefulness of TPS measurements during adenosine triphosphate (ATP) stress in assessing myocardial ischemia and to evaluate whether prolongation of TPS disappears immediately after percutaneous coronary intervention (PCI) or not.

METHODS AND RESULTS

A total of 26 patients underwent strain measurements before and after PCI. Corrected TPS for heart rate (TPSc) in target regions and in control regions were measured both at baseline and during ATP infusion. TPSc ratio was calculated as a ratio of TPSc during ATP stress to TPSc at baseline. TPSc in the target region significantly increased during ATP infusion before PCI, which was significantly longer than hyperemic TPSc in control regions. Accordingly, TPSc ratio in the target regions before PCI was significantly greater than that in control regions (1.22+/-0.17 vs 0.96+/-0.09, respectively, P<0.0001). Following PCI, the TPSc ratio in the target regions significantly decreased to 0.98+/-0.05 (P<0.0001). Receiver operating characteristic curve analysis provided a cut-off of 1.04 in TPSc ratio for detecting myocardial ischemia with a sensitivity of 93% and specificity of 93%.

CONCLUSIONS

TPS measurements during ATP stress differentiated target from control myocardium before PCI. The prolongation of TPSc disappeared immediately after PCI.