Could Pan-Immune-Inflammation Value be a Marker for the Diagnosis of Coronary Slow Flow Phenomenon?

Inflammation plays a key role in the pathogenesis of the coronary slow flow phenomenon (CSFP). The newly developed inflammatory marker, pan-immune-inflammation value (PIV), is associated with adverse cardiovascular events. This study investigated the predictive value of PIV for diagnosing CSFP in comparison to other inflammation-based markers. A total of 214 patients, 109 in the CSFP group and 105 in the normal coronary flow (NCF) group, were retrospectively included in the study. Coronary flow was calculated using the Thrombolysis in Myocardial Infarction frame count method. In addition to PIV, other inflammatory markers such as neutrophil-lymphocyte ratio, platelet-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) were calculated for the patients. The average age of patients was 50.3 ± 8.4, with a male ratio of 55.1%. Compared to the NCF group, patients in the CSFP group had higher levels of hyperlipidemia, glucose, triglyceride, NLR, PLR, SII, and PIV, while their high-density lipoprotein cholesterol (HDL-C), was lower (p < 0.05). Logistic regression analysis demonstrated that HDL-C, glucose, triglyceride, and PIV were independent predictor factors for CSFP (p < 0.05). PIV is a strong and independent predictor factor for CSFP and superior in predicting CSFP compared to other inflammatory markers.

Negative Impact of Acute Reloading after Mechanical Left Ventricular Unloading

Mechanical LV unloading for acute myocardial infarction (MI) is a promising supportive therapy to reperfusion. However, no data is available on exit strategy. We evaluated hemodynamic and cellular effects of reloading after Impella-mediated LV unloading in Yorkshire pigs. First, we conducted an acute study in normal heart to observe effects of unloading and reloading independent of MI-induced ischemic effects. We then completed an MI study to investigate optimal exit strategy on one-week infarct size, no-reflow area, and LV function with different reloading speeds. Initial studies showed that acute reloading causes an immediate rise in end-diastolic wall stress followed by a significant increase in cardiomyocyte apoptosis. The MI study did not result in any statistically significant findings; however, numerically smaller average infarct size and no-reflow area in the gradual reloading group prompt further examination of reloading approach as an important clinically relevant consideration.

Post-occlusive reactive hyperemia and skeletal muscle capillary hemodynamics

Post-occlusive reactive hyperemia (PORH) is an accepted diagnostic tool for assessing peripheral macrovascular function. While conduit artery hemodynamics have been well defined, the impact of PORH on capillary hemodynamics remains unknown, despite the microvasculature being the dominant site of vascular control. Therefore, the purpose of this investigation was to determine the effects of 5 min of feed artery occlusion on capillary hemodynamics in skeletal muscle. We tested the hypothesis that, upon release of arterial occlusion, there would be: 1) an increased red blood cell flux (fRBC) and red blood cell velocity (VRBC), and 2) a decreased proportion of capillaries supporting RBC flow compared to the pre-occlusion condition.

METHODS

In female Sprague-Dawley rats (n = 6), the spinotrapezius muscle was exteriorized for evaluation of capillary hemodynamics pre-occlusion, 5 min of feed artery occlusion (Occ), and 5 min of reperfusion (Post-Occ).

RESULTS

There were no differences in mean arterial pressure (MAP) or capillary diameter (Dc) between pre-occlusion and post-occlusion (P > 0.05). During 30 s of PORH, capillary fRBC was increased (pre: 59 ± 4 vs. 30 s-post: 77 ± 2 cells/s; P < 0.05) and VRBC was not changed (pre: 300 ± 24 vs. 30 s post: 322 ± 25 μm/s; P > 0.05). Capillary hematocrit (Hctcap) was unchanged across the pre- to post-occlusion conditions (P > 0.05). Following occlusion, there was a 20-30% decrease in the number of capillaries supporting RBC flow at 30 s and 300 s-post occlusion (pre: 92 ± 2%; 30 s-post: 66 ± 3%; 300 s-post: 72 ± 6%; both P < 0.05).

CONCLUSION

Short-term feed artery occlusion (i.e. 5 min) resulted in a more heterogeneous capillary flow profile with the presence of capillary no-reflow, decreasing the percentage of capillaries supporting RBC flow. A complex interaction between myogenic and metabolic mechanisms at the arteriolar level may play a role in the capillary no-reflow with PORH. Measurements at the level of the conduit artery mask significant alterations in blood flow distribution in the microcirculation.

Luteolin alleviates ischemia/reperfusion injury-induced no-reflow by regulating Wnt/β-catenin signaling in rats

The no-reflow phenomenon induced by ischemia-reperfusion (I/R) injury seriously limits the therapeutic value of coronary recanalization and leads to a poor prognosis. Previous studies have shown that luteolin (LUT) is a vasoprotective factor. However, whether LUT can be used to prevent the no-reflow phenomenon remains unknown. Positron emission tomography perfusion imaging, performed to detect the effects of LUT on the no-reflow phenomenon in vivo, revealed that LUT treatment was able to reduce the no-reflow area in rat I/R models. In vitro, LUT was shown to reduce the hypoxia-reoxygenation injury-induced endothelial permeability and apoptosis. The levels of malondialdehyde, reactive oxygen species and NADPH were also measured and the results indicated that LUT could inhibit the oxidative stress. Western blot analysis revealed that LUT protected endothelial cells from I/R injury by regulating the Wnt/β-catenin pathway. Overall, we concluded that the use of LUT to minimize I/R induced microvascular damage is a feasible strategy to prevent the no-reflow phenomenon.

Mechanism and potential treatment of the "no reflow" phenomenon after acute myocardial infarction: role of pericytes and GPR39

The "no reflow" phenomenon, where the coronary artery is patent after treatment of acute myocardial infarction (AMI) but tissue perfusion is not restored, is associated with worse outcome. The mechanism of no reflow is unknown. We hypothesized that pericytes contraction, in an attempt to maintain a constant capillary hydrostatic pressure during reduced coronary perfusion pressure, causes capillary constriction leading to no reflow and that this effect is mediated through the orphan receptor, GPR39, present in pericytes. We created AMI (coronary occlusion followed by reperfusion) in GPR39 knock out mice and littermate controls. In a separate set of experiments, we treated wild-type mice undergoing coronary occlusion with vehicle or VC43, a specific inhibitor of GPR39, before reperfusion. We found that no reflow zones were significantly smaller in the GPR39 knockouts compared with controls. Both no reflow and infarct size were also markedly smaller in animals treated with VC43 compared with vehicle. Immunohistochemistry revealed greater capillary density and larger capillary diameter at pericyte locations in the GPR39-knockout and VC43-treated mice compared with controls. We conclude that GPR39-mediated pericyte contraction during reduced coronary perfusion pressure causes capillary constriction resulting in no reflow during AMI and that smaller no reflow zones in GPR39-knockout and VC43-treated animals are associated with smaller infarct sizes. These results elucidate the mechanism of no reflow in AMI, as well as providing a therapeutic pathway for the condition.NEW & NOTEWORTHY The mechanism of "no reflow" phenomenon, where the coronary artery is patent after treatment of acute myocardial infarction but tissue perfusion is not restored, is unknown. This condition is associated with worse outcome. Here, we show that GPR39-mediated pericyte contraction during reduced coronary perfusion pressure causes capillary constriction resulting in no reflow. Smaller no-reflow zones in GPR39-knockout animals and those treated with a GPR39 inhibitor are associated with smaller infarct size. These results could have important therapeutic implications.

Effect of GP IIb/IIIa inhibitor duration on the clinical prognosis of primary percutaneous coronary intervention in ST-segment elevation myocardial infarction with no-/slow-reflow phenomenon

BACKGROUND

In patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) accompanied by the no-/slow-reflow phenomenon, the maintenance duration of GP IIb/IIIa inhibitor (GPI) is controversial. We compare the efficacy and safety of short- and long-term GPI infusion in STEMI patients with the no-/slow-reflow phenomenon.

METHODS

From June 2016 to December 2019, we continuously included patients with on-set STEMI who underwent pPCI, accompanied by the no-/slow-reflow, during interventional procedures at Guangdong Provincial People's Hospital and Zhuhai Golden Bay Hospital. The hemorrhage events, heart function, and major adverse cardiovascular events (MACE) were compared between < 24 h and ≥ 24 h GPI duration groups. The Kaplan-Meier curve was used to estimate the 1-year MACE-free survival at different GPI utility times.

RESULTS

In total, 127 patients were divided into two groups based on the duration of tirofiban use (less and more than 24 h). There was no significant difference between two groups in terms of baseline characteristics, plaque condition, and coronary physiological function. The two groups showed similar in-hospital MACE (1 [1.85%] vs. 4 [5.48%], p = 0.394) and 1-year MACE-free survival (log-rank test p = 0.9085). The 1-year MACE remained consistent between the two groups in all subgroups of different risk factors of no-/slow-reflow. There was no significant difference in heart function and in-hospital hemorrhage events (3.7% vs. 1.37%, p = 0.179).

CONCLUSION

In the real world, prolonging the duration of GPI may not significantly improve the clinical outcome in patients with STEMI with no-/slow-reflow.

CHA2DS2-VASc score predicts the slow flow/no-reflow phenomenon in ST-segment elevation myocardial infarction patients with multivessel disease undergoing primary percutaneous coronary intervention

ST-segment elevation myocardial infarction (STEMI) patients with multivessel disease (MVD) have a higher incidence of slow-flow/no-reflow (SF-NR) phenomenon during primary percutaneous coronary intervention (PPCI) than those with single vessel disease. Currently, no effective tools exist to predict the risk of SF-NR in this population. The present study aimed to evaluate whether CHA2DS2-VASc score can be used as a simple tool to predict this risk.This study consecutively included STEMI patients hospitalized in Beijing Anzhen Hospital from January 2005 to January 2015. Among these patients, 1032 patients with MVD were finally enrolled. Patients were divided into SF-NR (+) group and SF-NR (-) group according to whether SF-NR occurred during PPCI. SF-NR was defined as the thrombolysis in myocardial infarction (TIMI) grade ≤2.There were 134 patients (13%) in the SF-NR (+) group. Compared with the SF-NR (-) group, patients in the SF-NR (+) group are elder, with lower left ventricular ejection fraction and higher CHA2DS2-VASc score. Multiple logistic regression analysis indicated that CHA2DS2-VASc score ≥3 (odds ratio [OR], 2.148; 95% confidence interval [CI], 1.389-3.320; P = .001), current smoking (OR, 1.814; 95% CI, 1.19-2.764; P = .006), atrial fibrillation (OR, 2.892; 95% CI, 1.138-7.350; P = .03), complete revascularization (OR, 2.307; 95% CI, 1.202-4.429; P = .01), and total length of stents ≥40 mm (OR, 1.482; 95% CI, 1.011-2.172; P = .04) were independent risk factors of SF-NR. The incidence of SF-NR in patients with CHA2DS2-VASc score ≥3 was 1.7 times higher than that in patients with CHA2DS2-VASc score <3. Additionally, patients with CHA2DS2-VASc score ≥3 plus ≥2 risk factors have 3 times higher incidence of SF-NR than those with CHA2DS2-VASc score ≥3 plus 0 to 1 risk factor.CHA2DS2-VASc score ≥3 can be used as a simple and sensitive indicator to predict SF-NR phenomenon and guide the PPCI strategy in STEMI patients with MVD.

Tongmai Yangxin pill reduces myocardial No-reflow via endothelium-dependent NO-cGMP signaling by activation of the cAMP/PKA pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The Tongmai Yangxin pill (TMYX) is derived from the Zhigancao decoction recorded in Shang han lun by Zhang Zhongjing during the Han dynasty. TMYX is used for the clinical treatment of chest pain, heartache, and qi-yin-deficiency coronary heart disease. Previous studies have confirmed that TMYX can improve vascular endothelial function in patients with coronary heart disease by upregulating nitric oxide activity and then regulating vascular tension. Whether TMYX can further improve myocardial NR by upregulating NO activity and then dilating blood vessels remains unclear.

AIM OF THE STUDY

This study aimed to reveal whether TMYX can further improve myocardial NR by upregulating NO activity and then dilating blood vessels. The underlying cAMP/PKA and NO-cGMP signaling pathway-dependent mechanism is also explored.

MATERIALS AND METHODS

The left anterior descending coronary arteries of healthy adult male SD rats were ligated to establish the NR model. TMYX (4.0 g/kg) was orally administered throughout the experiment. Cardiac function was measured through echocardiography. Thioflavin S, Evans Blue, and TTC staining were used to evaluate the NR and ischemic areas. Pathological changes in the myocardium were assessed by hematoxylin-eosin staining. An automated biochemical analyzer and kit were used to detect the activities of myocardial enzymes and myocardial oxidants, including CK, CK-MB, LDH, reactive oxygen species, superoxide dismutase, malonaldehyde, and NO. The expression levels of genes and proteins related to the cAMP/PKA and NO/cGMP signaling pathways were detected via real-time fluorescence quantitative PCR and Western blot analysis, respectively. A microvascular tension sensor was used to detect coronary artery diastolic function in vitro.

RESULTS

TMYX elevated the EF, FS, LVOT peak, LVPWd and LVPWs values, decreased the LVIDd, LVIDs, LV-mass, IVSd, and LV Vols values, demonstrating cardio-protective effects, and reduced the NR and ischemic areas. Pathological staining showed that TMYX could significantly reduce inflammatory cell number and interstitial edema. The activities of CK, LDH, and MDA were reduced, NO activity was increased, and oxidative stress was suppressed after treatment with TMYX. TMYX not only enhanced the expression of Gs-α, AC, PKA, and eNOS but also increased the expression of sGC and PKG. Furthermore, TMYX treatment significantly decreased ROCK expression. We further showed that TMYX (25-200 mg/mL) relaxed isolated coronary microvessels.

CONCLUSIONS

TMYX attenuates myocardial NR after ischemia and reperfusion by activating the cAMP/PKA and NO/cGMP signaling pathways, further upregulating NO activity and relaxing coronary microvessels.

Clinical characteristics in patients with coronary slow flow phenomenon: A retrospective study

ABSTRACT

Coronary slow flow phenomenon (CSFP) is a coronary artery disease in which coronary angiography shows no obvious stenosis, but there is a delay in blood flow perfusion. The etiopathogenic mechanisms of CSFP are still unclear. The aim of the present study was to investigate the role of clinical characteristics in patients with CSFP, and to provide a reference for exploring the potential mechanisms of CSFP. Patients with angiographically normal epicardial arteries were enrolled (145 patients with CSFP and 145 normal controls). Collected clinical information and laboratory indexes, which measured by peripheral venous blood samples before coronary angiography. Logistic regression analysis was performed for statistical analysis. The present study found 19 clinical and laboratory indexes with statistical differences between the two groups in univariate analysis. Multivariate analysis showed that monocyte count, haemoglobin, serum creatinine and globulin were independent predictors of CSFP. Moreover, the monocyte count, haemoglobin, creatinine and globulin levels were significantly higher in the CSFP patients than the controls, with positive associations between these parameters and the extent of CSFP. In addition, ROC analysis showed the diagnostic value of the above indexes for CSFP.

In-Hospital Peak Glycemia in Predicting No-Reflow Phenomenon in Diabetic Patients with STEMI Treated with Primary Percutaneous Coronary Intervention

Although percutaneous coronary intervention (PCI) significantly improves the prognosis for myocardial infarction, the no-reflow phenomenon is still the major adverse complication of PCI leading to increased mortality, especially for the patients with ST-segment elevation myocardial infarction (STEMI) combined with diabetes. To reduce the occurrence of no-reflow, prognostic factors must be identified for no-reflow phenomenon before PCI. A total of 262 participants with acute STEMI and diabetes were recruited into our cardiovascular center and underwent primary PCI for the analyses of prognostic factors of no-reflow. The patients were divided into two groups according to thrombolysis in myocardial infarction (TIMI): the normal flow and no-reflow groups, and related factors were analyzed with different statistical methods. In the present investigation, the in-hospital peak glycemia was significantly higher in the no-reflow group than the normal flow group, while more narrowed vessels, higher level of initial TIMI flow, were observed in the patients of the no-reflow group. A multivariate logistic regression analysis further demonstrated that peak glycemia was an independent predictor for no-reflow in the diabetic patients with STEMI. Our data indicated the importance of the proper control of glucose before PCI for the diabetic patients with STEMI before PCI to reduce the occurrence of the no-reflow after operation.

Tongmai Yangxin pill reduces myocardial no-reflow by regulating apoptosis and activating PI3K/Akt/eNOS pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tongmai Yangxin pill (TMYX) is derived from the Zhigancao decoction recorded in Shang han lun by Zhang Zhongjing during the Han dynasty and was further improved by Professor Ruan Shiyi, a cardiovascular expert at Tianjin University of Traditional Chinese Medicine. TMYX is used for the clinical treatment of chest pain, heartache, and qi-yin-deficiency coronary heart disease and can improve vascular endothelial function in patients with angina pectoris or coronary heart disease by up-regulating nitric oxide activity and then regulating vascular tension. Whether TMYX can further improve myocardial no-reflow by up-regulating NO activity and then dilating blood vessels remains unclear.

AIM OF THE STUDY

This study aimed to reveal whether TMYX can further improve myocardial NR by up-regulating NO activity and then dilating blood vessels. The mechanism underlying PI3K/Akt/eNOS pathway activation and apoptosis regulation is also explored.

MATERIALS AND METHODS

The left anterior descending coronary arteries of healthy adult male SD rats were ligated to establish a NR model. The rats were assigned to 14 groups: control, sham, NR, TMYX (4.0 g/kg), sodium nitroprusside (SNP), Tongxinluo capsule (TXL), PI3K blocker (LY), TMYX + LY, SNP + LY, TXL + LY, eNOS blocker (L-NAME), TMYX + L-NAME, SNP + L-NAME, and TXL + L-NAME groups. Cardiac function was measured through echocardiography. Thioflavin S, Evans Blue, and TTC staining were adopted to evaluate NR and ischemic areas. Cell inflammation degree and edema were assessed by hematoxylin-eosin staining. Automated biochemical analyzer and kit were used to detect the activities of myocardial oxidants, including reactive oxygen species, super oxide dismutase, malonaldehyde, and NO. The expression levels of genes and proteins in the PI3K/Akt/eNOS signaling pathway and apoptosis were detected via real-time fluorescence quantitative PCR and Western blot analysis, respectively. A microvascular tension sensor was adopted to detect coronary artery diastolic function in vitro.

RESULTS

TMYX reduced NR and ischemic areas; suppressed LV-mass; enhanced EF, FS, LVOT peak, and LVSV; and improved cardiac structure and function. Moreover, it decreased creatine kinase (CK), CK-MB, and lactic dehydrogenase activities. TMYX increased NO and super oxide dismutase activities; inhibited malonaldehyde activity; reduced muscle fiber swelling and inflammatory cell infiltration; and improved vasodilation in vitro. In the NR myocardium, TMYX stimulated myocardial PI3K activities and PI3K (Tyr458) phosphorylation and enhanced Akt activities and Akt phosphorylation at Tyr315. TMYX increased the activities of eNOS and the phosphorylation of eNOS at Ser¹¹⁷⁷ in the NR myocardium and attenuated cardiomyocyte apoptosis by increasing the expression of Bcl-2 and decreasing that of caspase-3 and Bax. All these effects of TMYX were abolished by the specific inhibitors of PI3K (LY) and eNOS (L-NAME).

CONCLUSIONS

TMYX attenuates myocardial NR after ischemia and reperfusion by activating the PI3K/Akt/eNOS pathway and regulating apoptosis, further up-regulating NO activity and relaxing coronary microvessels.

Comparative Significance of Invasive Measures of Microvascular Injury in Acute Myocardial Infarction

BACKGROUND

The resistive reserve ratio (RRR) expresses the ratio between basal and hyperemic microvascular resistance. RRR measures the vasodilatory capacity of the microcirculation. We compared RRR, index of microcirculatory resistance (IMR), and coronary flow reserve (CFR) for predicting microvascular obstruction (MVO), myocardial hemorrhage, infarct size, and clinical outcomes, after ST-segment-elevation myocardial infarction.

METHODS

In the T-TIME trial (Trial of Low-Dose Adjunctive Alteplase During Primary PCI), 440 patients with acute ST-segment-elevation myocardial infarction from 11 UK hospitals were prospectively enrolled. In a subset of 144 patients, IMR, CFR, and RRR were measured post-primary percutaneous coronary intervention. MVO extent (% left ventricular mass) was determined by cardiovascular magnetic resonance imaging at 2 to 7 days. Infarct size was determined at 3 months. One-year major adverse cardiac events, heart failure hospitalizations, and all-cause death/heart failure hospitalizations were assessed.

RESULTS

In these 144 patients (mean age, 59±11 years, 80% male), median IMR was 29.5 (interquartile range: 17.0-55.0), CFR was 1.4 (1.1-2.0), and RRR was 1.7 (1.3-2.3). MVO occurred in 41% of patients. IMR>40 was multivariably associated with more MVO (coefficient, 0.53 [95% CI, 0.05-1.02]; P=0.031), myocardial hemorrhage presence (odds ratio [OR], 3.20 [95% CI, 1.25-8.24]; P=0.016), and infarct size (coefficient, 5.05 [95% CI, 0.84-9.26]; P=0.019), independently of CFR≤2.0, RRR≤1.7, myocardial perfusion grade≤1, and Thrombolysis in Myocardial Infarction frame count. RRR was multivariably associated with MVO extent (coefficient, -0.60 [95% CI, -0.97 to -0.23]; P=0.002), myocardial hemorrhage presence (OR, 0.34 [95% CI, 0.15-0.75]; P=0.008), and infarct size (coefficient, -3.41 [95% CI, -6.76 to -0.06]; P=0.046). IMR>40 was associated with heart failure hospitalization (OR, 5.34 [95% CI, 1.80-15.81] P=0.002), major adverse cardiac events (OR, 4.46 [95% CI, 1.70-11.70] P=0.002), and all-cause death/ heart failure hospitalization (OR, 4.08 [95% CI, 1.55-10.79] P=0.005). RRR was associated with heart failure hospitalization (OR, 0.44 [95% CI, 0.19-0.99] P=0.047). CFR was not associated with infarct characteristics or clinical outcomes.

CONCLUSIONS

In acute ST-segment-elevationl infarction, IMR and RRR, but not CFR, were associated with MVO, myocardial hemorrhage, infarct size, and clinical outcomes. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02257294.

Pathophysiology and diagnosis of coronary microvascular dysfunction in ST-elevation myocardial infarction

Early mechanical reperfusion of the epicardial coronary artery by primary percutaneous coronary intervention (PCI) is the guideline-recommended treatment for ST-elevation myocardial infarction (STEMI). Successful restoration of epicardial coronary blood flow can be achieved in over 95% of PCI procedures. However, despite angiographically complete epicardial coronary artery patency, in about half of the patients perfusion to the distal coronary microvasculature is not fully restored, which is associated with increased morbidity and mortality. The exact pathophysiological mechanism of post-ischaemic coronary microvascular dysfunction (CMD) is still debated. Therefore, the current review discusses invasive and non-invasive techniques for the diagnosis and quantification of CMD in STEMI in the clinical setting as well as results from experimental in vitro and in vivo models focusing on ischaemic-, reperfusion-, and inflammatory damage to the coronary microvascular endothelial cells. Finally, we discuss future opportunities to prevent or treat CMD in STEMI patients.

Association between impaired cutaneous microvascular endothelial function and lectin-like oxidized low-density lipoprotein receptor-1 in patients with coronary slow flow

OBJECTIVE

Although increasing studies indicate coronary slow flow (CSF) is a systemic microvascular disorder, whether there is impaired cutaneous microvascular endothelial function in CSF patients remains unclear. This study was designed to test the hypothesis that the cutaneous microvascular endothelial function of CSF patients is impaired and correlates with lectin-like oxidized low-density lipoprotein receptor-1(LOX-1).

METHODS

39 patients with CSF and 45 controls with normal coronary flow were enrolled. Velocity of coronary flow was quantitatively identified by thrombolysis in myocardial infarction frame count (TFC) method. LSCI system was used to assess subjects' cutaneous blood flow at rest and during PORH. Serum soluble LOX-1(sLOX-1) level was measured in all study subjects.

RESULTS

PORH-induced vasodilation was significantly reduced in CSF group in comparison with control group (0.26 ± 0.10 vs 0.35 ± 0.07 APU/mmHg, P < 0.001) and negatively correlated with the mean TFC for three coronary arteries (r = -0.385, P = 0.016). Serum sLOX-1 level in CSF group was significantly increased (582.93 ± 74.89 vs 483.64 ± 51.38 pg/ml, P < 0.001) and positively correlated with mean TFC(r = 0.467, P = 0.003).PORH response amplitudes had a significantly negative relationship with serum sLOX-1 level in CSF patients (r = -0.588, P < 0.001).

CONCLUSION

These data suggest that cutaneous microvascular endothelial function is impaired in patients with CSF, which is closely associated with increased LOX-1 expression.

Evaluation of left atrial volume and function in patients with coronary slow flow phenomenon using real-time three-dimensional echocardiography

This study aimed to evaluate the left atrial (LA) volume and phasic functions using real-time three-dimensional echocardiography (RT3DE) in coronary slow flow phenomenon (CSFP) patients with preserved left ventricular ejection fraction (LVEF). 56 patients with CSFP (36 males, 20 females) and 48 controls with normal coronary flow (27 males, 21 females) were prospectively enrolled. Comprehensive transthoracic echocardiographic examination and RT3DE for the assessment of LA dynamics were performed in all participants. LA maximum, minimum, and pre-atrial contraction volumes (LAV-max, LAV-min, and LAV-preA) were obtained for every subject. Conventional echocardiographic parameters, except for isovolumetric relaxation time and transmitral deceleration time, did not differ in two groups. RT3DE demonstrated higher LAV-max, LAV-min, LAV-preA, indexed LAV-max (LAVi-max), LA total emptying volume, and LA active emptying volume and fraction for CSFP patients compared with controls (all P < 0.05). In addition, LA total emptying fraction and LA passive emptying fraction were found to be lower in CSFP patients than in controls (all P < 0.05). Moreover, there were positive correlations between mean thrombolysis in myocardial infarction frame count values and LAV-max, LAV-min, LAV-preA, LAVi-max, and LA total and active emptying volumes. CSFP was associated with enlarged LA volumes, impaired LA reservoir and conduit function and enhanced contractile function. Evaluation of LA dynamics using RT3DE could facilitate recognition of subtle myocardial alterations related with CSFP.

The coronary circulation in acute myocardial ischaemia/reperfusion injury: a target for cardioprotection

The coronary circulation is both culprit and victim of acute myocardial infarction. The rupture of an epicardial atherosclerotic plaque with superimposed thrombosis causes coronary occlusion, and this occlusion must be removed to induce reperfusion. However, ischaemia and reperfusion cause damage not only in cardiomyocytes but also in the coronary circulation, including microembolization of debris and release of soluble factors from the culprit lesion, impairment of endothelial integrity with subsequently increased permeability and oedema formation, platelet activation and leucocyte adherence, erythrocyte stasis, a shift from vasodilation to vasoconstriction, and ultimately structural damage to the capillaries with eventual no-reflow, microvascular obstruction (MVO), and intramyocardial haemorrhage (IMH). Therefore, the coronary circulation is a valid target for cardioprotection, beyond protection of the cardiomyocyte. Virtually all of the above deleterious endpoints have been demonstrated to be favourably influenced by one or the other mechanical or pharmacological cardioprotective intervention. However, no-reflow is still a serious complication of reperfused myocardial infarction and carries, independently from infarct size, an unfavourable prognosis. MVO and IMH can be diagnosed by modern imaging technologies, but still await an effective therapy. The current review provides an overview of strategies to protect the coronary circulation from acute myocardial ischaemia/reperfusion injury. This article is part of a Cardiovascular Research Spotlight Issue entitled 'Cardioprotection Beyond the Cardiomyocyte', and emerged as part of the discussions of the European Union (EU)-CARDIOPROTECTION Cooperation in Science and Technology (COST) Action, CA16225.

The predictors of no reflow phenomenon after percutaneous coronary intervention in patients with ST elevation myocardial infarction: A meta-analysis

OBJECTIVE

To investigate the no reflow risk factors after percutaneous coronary intervention in ST elevation myocardial infarction patients.

METHOD

Sample size, mean±standard deviation (SD) or frequencies (percent) of normal and no reflow groups were extracted from each study.

RESULTS

Of 27 retrospective and prospective studies, we found that increasing risks of no reflow were associated with advanced age, male, family history of coronary artery disease, smoking, diabetes mellitus, hypertension, delayed reperfusion, killip class ≥2, elevated blood glucose, increased creatinine, elevated creatine kinase (CK), higher heart rate, decreased left ventricular ejection fraction (LVEF), collateral flow ≤1, longer lesion length, multivessel disease, reference luminal diameter, initial thrombolysis in myocardial infarction (TIMI) flow, and high thrombus burden. Moreover, initial TIMI flow ≤1 and high thrombus burden had the greater impact on no reflow (OR95%CI=3.83 [2.77-5.29], p<0.0001 and 3.69 [2.39-5.68], p<0.0001, respectively).

CONCLUSION

Our meta-analysis reveals that initial TIMI flow ≤1 and high thrombus burden are the most impacted no reflow risk factors.

Clinical, demographic, risk factor and angiographic profile of coronary slow flow phenomenon: A single centre experience

Background

The coronary slow flow phenomenon (CSFP) is an angiographic finding characterized by delayed distal vessel opacification in the absence of significant epicardial coronary stenosis. Although it is well-known to interventional cardiologists for approximately four decades, the etiopathogenesis still remains unclear.

Aims and objectives

In this study, we aimed to determine the clinical, demographic, risk factor and angiographic profile of patients with CSFP.

Methods

Clinical, demographic, risk factor and angiographic profile were recorded in all consecutive patients who had undergone coronary angiography between September 2016 and March 2017 and showed features of CSFP and a control group who showed normal coronary flow (NCF). The CSFP was diagnosed on the basis of the corrected thrombolysis in myocardial infarction frame count.

Results

CSFP was significantly more prevalent in male patients. Among the traditional risk factors, there was significantly more prevalence of hypertension (31.25% versus 6.67%, p < 0.001), dyslipidemia (40% versus 7.5%, p < 0.001) and history of tobacco use (47.5% versus 10.0%, p < 0.001) in CSFP patients as compared to NCF patients. On multivariable regression analysis hypertension, dyslipidemia, history of smoking and tobacco chewing were found to have independent association with CSFP. Acute coronary syndrome (ACS) was the most common mode of presentation in CSFP patients.

Conclusion

CSFP was relatively common among patients who presented with ACS. Hypertension, dyslipidemia, smoking and tobacco chewing can be considered independent risk factors for this phenomenon. Therefore, CSFP should be considered as a pathological entity and not an entirely benign condition.

New and revisited approaches to preserving the reperfused myocardium

Early coronary artery reperfusion improves outcomes for patients with ST-segment elevation myocardial infarction (STEMI), but morbidity and mortality after STEMI remain unacceptably high. The primary deficits seen in these patients include inadequate pump function, owing to rapid infarction of muscle in the first few hours of treatment, and adverse remodelling of the heart in the months that follow. Given that attempts to further reduce myocardial infarct size beyond early reperfusion in clinical trials have so far been disappointing, effective therapies are still needed to protect the reperfused myocardium. In this Review, we discuss several approaches to preserving the reperfused heart, such as therapies that target the mechanisms involved in mitochondrial bioenergetics, pyroptosis, and autophagy, as well as treatments that harness the cardioprotective properties of inhaled anaesthetic agents. We also discuss potential therapies focused on correcting the no-reflow phenomenon and its effect on healing and adverse left ventricular remodelling.

The role of left ventricular deformation in the assessment of microvascular obstruction and intramyocardial haemorrhage

In the setting of acute ST-elevation myocardial infarction (STEMI), it remains unclear which strain parameter most strongly correlates with microvascular obstruction (MVO) or intramyocardial haemorrhage (IMH). We aimed to investigate the association of MVO, IMH and convalescent left ventricular (LV) remodelling with strain parameters measured with cardiovascular magnetic resonance (CMR). Forty-three patients with reperfused STEMI and 10 age and gender matched healthy controls underwent CMR within 3-days and at 3-months following reperfused STEMI. Cine, T2-weighted, T2*-imaging and late gadolinium enhancement (LGE) imaging were performed. Infarct size, MVO and IMH were quantified. Peak global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS) and their strain rates were derived by feature tracking analysis of LV short-axis, 4-chamber and 2-chamber cines. All 43 patients and ten controls completed the baseline scan and 34 patients completed 3-month scans. In multivariate regression, GLS demonstrated the strongest association with MVO or IMH (beta = 0.53, p < 0.001). The optimal cut-off value for GLS was −13.7% for the detection of MVO or IMH (sensitivity 76% and specificity 77.8%). At follow up, 17% (n = 6) of patients had adverse LV remodeling (defined as an absolute increase of LV end-diastolic/end-systolic volumes >20%). Baseline GLS also demonstrated the strongest diagnostic performance in predicting adverse LV remodelling (AUC = 0.79; 95% CI 0.60–0.98; p = 0.03). Post-reperfused STEMI, baseline GLS was most closely associated with the presence of MVO or IMH. Baseline GLS was more strongly associated with adverse LV remodelling than other CMR parameters.

Limitation of Infarct Size and No-Reflow by Intracoronary Adenosine Depends Critically on Dose and Duration

OBJECTIVES

In the absence of effective clinical pharmacotherapy for prevention of reperfusion-mediated injury, this study re-evaluated the effects of intracoronary adenosine on infarct size and no-reflow in a porcine model of acute myocardial infarction using clinical bolus and experimental high-dose infusion regimens.

BACKGROUND

Despite the clear cardioprotective effects of adenosine, when administered prior to ischemia, studies on cardioprotection by adenosine when administered at reperfusion have yielded contradictory results in both pre-clinical and clinical settings.

METHODS

Swine (54 ± 1 kg) were subjected to a 45-min mid-left anterior descending artery occlusion followed by 2 h of reperfusion. In protocol A, an intracoronary bolus of 3 mg adenosine injected over 1 min (n = 5) or saline (n = 10) was administered at reperfusion. In protocol B, an intracoronary infusion of 50 μg/kg/min adenosine (n = 15) or saline (n = 21) was administered starting 5 min prior to reperfusion and continued throughout the 2-h reperfusion period.

RESULTS

In protocol A, area-at-risk, infarct size, and no-reflow were similar between groups. In protocol B, risk zones were similar, but administration of adenosine resulted in significant reductions in infarct size from 59 ± 3% of the area-at-risk in control swine to 46 ± 4% (p = 0.02), and no-reflow from 49 ± 6% of the infarct area to 26 ± 6% (p = 0.03).

CONCLUSIONS

During reperfusion, intracoronary adenosine can limit infarct size and no-reflow in a porcine model of acute myocardial infarction. However, protection was only observed when adenosine was administered via prolonged high-dose infusion, and not via short-acting bolus injection. These findings warrant reconsideration of adenosine as an adjuvant therapy during early reperfusion.

Layer-specific analysis of left ventricular myocardial contractility in patients with coronary slow-flow phenomenon

PURPOSE

Coronary slow-flow phenomenon (CSFP) is an angiographic diagnosis characterized by delayed coronary opacification in the absence of significant epicardial coronary stenosis. We previously reported impaired left ventricular (LV) function in patients with CSFP. However, the LV wall comprises three myocardial layers whose contractility can be differently affected. Therefore, we evaluated layer-specific (endocardial, mid-myocardial, and epicardial) LV myocardial contractility and assessed its relationships with the number of affected coronary arteries and their flow.

METHODS

We studied 60 patients with CSFP and 46 controls. CSFP was diagnosed by thrombolysis in myocardial infarction frame count. Echocardiography was performed within 72 hours after the coronary angiography. LV layer-specific longitudinal strain (LS) was measured using two-dimensional speckle-tracking echocardiography.

RESULTS AND CONCLUSIONS

The LS of all three myocardial layers was lower in patients with CSFP than in controls. In patients with CSFP, LS of all three myocardial layers and transmural LS gradient correlated negatively with the number of affected coronary arteries and the mean thrombolysis in myocardial infarction frame count. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:429-436, 2016.

HEMATOLOGICAL MARKERS OF THE NO-REFLOW PHENOMEN ON IN-PATIENTS UNDERGOING PRIMARY PERCUTANEOUS CORONARY INTERVENTION

The study aims to investigate hematological parameters of the no-reflow phenomenon (NRP) developed in patients underwent primary percutaneous coronary intervention (pPCI) due to diagnosis of ST elevation myocardial infarction (STEMI). The study sample consisted of a total of 90 patients, of which 44 patients who underwent pPCI and developed NRP without anemia and chronic renal failure (mean age was 64; 34 males and 10 females) were included in the experimental group, and the control group consisted of 46 patients with normal reperfusion flow (mean age was 58; 34 males and 12 females). In both groups, Red blood-cell Distribution Width (RDW), Mean Platelet Volume (MPV), plateletcrit (PCT), Platelet Distribution Width (PDW), and neutrophil count were observed. The demographic characteristics of both groups were similar, except the higher mean age of the experimental group (age; 64.0±12.6; 58.0±12.5). No correlation was found between development of no-reflow and incidence of risk factors such as hypertension, diabetes mellitus, dyslipidemia, smoking, family history and gender. In the no-reflow group, RDW level (16.2%±2.1; 14.2%±0.7, p<0.001), MPV level (7.9±1.2; 7.3±0.8, p<0.05), PDW level (18.1±1.2; 17.4±1.2, p<0.05), PCT level (0.2±0.06 vs 0.17±0.05) and neutrophil count (9.9±3.7; 7.1±3.3, p<0.001) was found to be higher than the control group. According to logistic regression analysis, RDW (OR; 23.4, <95% Cl 4.6-118.9, p<0.001), PDW (OR; 2.8, <95% Cl 1.2-6.4, p<0.05) and neutrophil count (OR; 1.4, Cl 1.1-1.9, p<0.05) were found to be the predictors of NRP development. Hemogram is a cheap and easy to apply test. In our study, a relationship between the NRP development and RDW, PDW, MPV, PCT, and neutrophil counts was found in patients who underwent pPCI. At the same time, RDW, PDW, and the neutrophil count were found to be predictors of no-reflow development.

Distal coronary embolization following acute myocardial infarction increases early infarct size and late left ventricular wall thinning in a porcine model

BACKGROUND

Distal coronary embolization (DCE) of thrombotic material occurs frequently during percutaneous interventions for acute myocardial infarction and can alter coronary flow grades. The significance of DCE on infarct size and myocardial function remains unsettled. The aims of this study were to evaluate the effects of DCE sufficient to cause no-reflow on infarct size, cardiac function and ventricular remodeling in a porcine acute myocardial infarction model.

METHODS AND RESULTS

Female Yorkshire pigs underwent 60 min balloon occlusion of the left anterior descending coronary artery followed by reperfusion and injection of either microthrombi (prepared from autologous porcine blood) sufficient to cause no-reflow (DCE), or saline (control). Animals were sacrificed at 3 h (n = 5), 3 days (n = 20) or 6 weeks (n = 20) post-AMI. Cardiovascular magnetic resonance (CMR), serum troponin-I, and cardiac gelatinase (MMP) and survival kinase (Akt) activities were assessed. At 3d, DCE increased infarct size (CMR: 18.8% vs. 14.5%, p = 0.04; serum troponin-I: 13.3 vs. 6.9 ng/uL, p < 0.05) and MMP-2 activity levels (0.81 vs. 0.49, p = 0.002), with reduced activation of Akt (0.06 versus 0.26, p = 0.02). At 6 weeks, there were no differences in infarct size, ventricular volume or ejection fraction between the two groups, although infarct transmurality (70% vs. 57%, p< 0.04) and ventricular thinning (percent change in mid anteroseptal wall thickness:-25.6% vs. 0.7%, p = 0.03) were significantly increased in the DCE group.

CONCLUSIONS

DCE increased early infarct size, but without affecting later infarct size, cardiac function or ventricular volumes. The significance of the later remodelling changes (ventricular thinning and transmurality) following DCE, possibly due to changes in MMP-2 activity and Akt activation, merits further study.

Effect of microvascular obstruction and intramyocardial hemorrhage by CMR on LV remodeling and outcomes after myocardial infarction: a systematic review and meta-analysis

The goal of this systematic analysis is to provide a comprehensive review of the current cardiac magnetic resonance data on microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH). Data related to the association of MVO and IMH in patients with acute myocardial infarction (MI) with left ventricular (LV) function, volumes, adverse LV remodeling, and major adverse cardiac events (MACE) were critically analyzed. MVO is associated with a lower ejection fraction, increased ventricular volumes and infarct size, and a greater risk of MACE. Late MVO is shown to be a stronger prognostic marker for MACE and cardiac death, recurrent MI, congestive heart failure/heart failure hospitalization, and follow-up LV end-systolic volumes than early MVO. IMH is associated with LV remodeling and MACE on pooled analysis, but because of limited data and heterogeneity in study methodology, the effects of IMH on remodeling require further investigation.

Assessment of left and right ventricular diastolic and systolic functions using two-dimensional speckle-tracking echocardiography in patients with coronary slow-flow phenomenon

OBJECTIVE

Coronary slow-flow phenomenon (CSFP) is an angiographic diagnosis characterised by a low rate of flow of contrast agent in the normal or near-normal epicardial coronary arteries. Many of the patients with CSFP may experience recurrent acute coronary syndromes. However, current clinical practice tends to underestimate the impact of CSFP due to the yet unknown effect on the cardiac function. This study was performed to evaluate left ventricular (LV) and right ventricular (RV) diastolic and systolic functions, using two-dimensional (2D) longitudinal strain and strain rate, in patients with CSFP, and to determine the relationships between the thrombolysis in myocardial infarction (TIMI) frame count (TFC) and LV and RV diastolic and systolic functions.

METHODS

Sixty-three patients with CSFP and 45 age- and sex-matched controls without CSFP were enrolled in the study. Diagnosis of CSFP was made by TFC. LV and RV diastolic and systolic functions were assessed by 2D speckle-tracking echocardiography.

RESULTS

LV peak early diastolic longitudinal strain rate (LSRe) was lower in patients with CSFP than in controls (P = 0.01). LV peak systolic longitudinal strain (LS) and LV peak systolic longitudinal strain rate (LSRs) were lower in patients with CSFP than in controls (P = 0.004 and P = 0.03, respectively). There was no difference in LV ejection fraction. RV peak early diastolic longitudinal strain rate (RSRe) was lower in patients with CSFP than in controls (P = 0.03). There were no differences in RV peak systolic longitudinal strain (RS), RV peak systolic longitudinal strain rate (RSRs), or RV fractional area change among the groups. The mean TFC correlated negatively with LSRe and RSRe in patients with CSFP (r = -0.26, P = 0.04 and r = -0.32, P = 0.01, respectively).

CONCLUSIONS

LV diastolic and systolic functions were impaired in patients with CSFP. CSFP also affected RV diastolic function, but not RV systolic function.

Coronary slow flow phenomenon associated with high serum levels of soluble CD40 ligand and urotensin II: a multi-marker approach

BACKGROUND

The aim of this study was to evaluate the serum soluble CD40 ligand (sCD40L) levels, serum uroten- sin II levels, and serum leptin levels as an indirect indicator of endothelial dysfunction, inflammation, and atherosclerosis at the microvascular level, and the comparison of those values with those of the control group with a nor- mal coronary flow pattern.

METHODS

The study included 35 consecutive patients (17 women, 18 men; average age: 51.20 ± 10.93 years) in our hospital who underwent coronary angiography due to objective myocardial ischemia and in whom slow coronary flow was detected. The control group included 34 consecutive patients with normal coronary flow pattern (18 women, 16 men; average age: 54.59 ± 12.40 years). The coronary flow rates of all patients and control subjects were documented by the thrombolysis in myocardial infarction (TIMI) frame count. Serum sCD40L concentrations, serum urotensin II concentrations and serum leptin concentrations were measured by an enzyme-linked immunosorbent assay method using commercially available kits.

RESULTS

The corrected TIMI frame count for LAD, Cx, RCA, and mean TIMI frame count were significantly higher in patients with slow coronary flow (SCF), compared to subjects with normal coronary flow (43.8 ± 1.7 vs. 17.7 ± 4.7, p < 0.001; 27.9 ± 6.9 vs. 11.9 ± 4.8, p < 0.001; 25.4 ± 8.4 vs. 11.1 ± 3.1, p < 0.001; and 32.3 ± 6.4 vs. 13.7 ± 5, p < 0.001, respectively). The serum soluble CD40 ligand and serum urotensin II levels were significantly higher in the slow coronary flow group compared to the control group (12.00 ± 5.43 ng/mL--6.49 ± 5.03 ng/mL, p < 0.001; and 50.94 ± 34.28 pg/mL--26.91 ± 11.52 pg/mL, p < 0.001, respectively). In addition, there was no statistically significant difference between the slow coronary flow group and the control group with regard to serum leptin levels and hs-CRP levels (both p > 0.05).

CONCLUSIONS

This study suggests that soluble CD40 ligand and urotensin II likely play a role in the pathogenesis of slow coronary flow.

[Coronary microvascular obstruction phenomenon after endovascular recanalization in patients with chronic coronary occlusions]

The article analyzed no-reflow phenomenon after endovascular recanalization for chronic coronary occlusion. An assessment of antegrade blood flow was made while performing the coronary angiography according to TIMI classification. The Rentrop scale was used for evaluation of retrograde blood flow. The results of investigation showed, that the frequency of occurrence of no-reflow phenomenon after endovascular recanalization in the case of chronic coronary occlusion wasn't higher than 5%. The onset of no-reflow phenomenon after endovascular recanalization in chronic coronary occlusion doesn't depend on the volume of retrograde collateral filling of distal coronary bloodstream. A postponed restoration of antegrade blood flow was possible in patients with previously manifested (Rentrop II-III) retrograde collateral filling of periphery.

Arterial elasticity in obese subjects with coronary slow flow phenomenon

BACKGROUND

Coronary slow flow phenomenon (CSFP) is a functional and structural disease that is diagnosed by coronary angiogram.

OBJECTIVES

To evaluate the possible association between CSFP and small artery elasticity in an effort to understand the pathogenesis of CSFP.

METHODS

The study population comprised 12 patients with normal coronary arteries and CSFP and 12 with normal coronary arteries without CSFP. We measured conjugated diene formation at 234 nm during low density lipoprotein (LDL) oxidation, as well as platelet aggregation. We estimated, noninvasively, arterial elasticity parameters. Mann-Whitney nonparametric test was used to compare differences between the groups. Data are presented as mean +/- standard deviation.

RESULTS

Waist circumference was 99.2 +/- 8.8 cm and 114.9 +/- 10.5 cm in the normal flow and CSFP groups, respectively (P = 0.003). Four patients in the CSFP group and one in the normal flow group had type 2 diabetes. Area under the curve in the oral glucose tolerance test was 22% higher in the CSFP than in the normal group (P = 0.04). There was no difference in systolic and diastolic blood pressure, plasma concentrations of total cholesterol, triglycerides, high density lipoprotein, LDL and platelet aggregation parameters between the groups. Lag time required until initiation of LDL oxidation in the presence of CuSO4 was 17% longer (P = 0.02) and homocysteine fasting plasma concentration was 81% lower (P = 0.05) in the normal flow group. Large artery elasticity was the same in both groups. Small artery elasticity was 5 +/- 1.5 ml/mmHg x 100 in normal flow subjects and 6.1 +/- 1.9 ml/mmHg x 100 in the CSFP patients (P = 0.02).

CONCLUSIONS

Patients with CSFP had more metabolic derangements. Arterial stiffness was not increased in CSFP.

The effect of microvascular obstruction and intramyocardial hemorrhage on contractile recovery in reperfused myocardial infarction: insights from cardiovascular magnetic resonance

BACKGROUND

Following acute myocardial infarction (AMI), microvascular obstruction (MO) and intramyocardial hemorrhage (IMH) adversely affect left ventricular remodeling and prognosis independently of infarct size. Whether this is due to infarct zone remodeling, changes in remote myocardium or other factors is unknown. We investigated the role of MO and IMH in recovery of contractility in infarct and remote myocardium.

METHODS

Thirty-nine patients underwent cardiovascular magnetic resonance (CMR) with T2-weighted and T2* imaging, late gadolinium enhancement (LGE) and myocardial tagging at 2, 7, 30 and 90 days following primary percutaneous coronary intervention for AMI. Circumferential strain in infarct and remote zones was stratified by presence of MO and IMH.

RESULTS

Overall, infarct zone strain recovered with time (p < 0.001). In the presence of MO with IMH and without IMH, epicardial strain recovered (p = 0.03, p < 0.01 respectively), but mid-myocardial or endocardial strain did not (mid-myocardium: p = 0.05, p = 0.12; endocardium: p = 0.27, p = 0.05, respectively). By day 90, infarcts with MO had more attenuated strain in all myocardial layers compared to infarcts without MO (p < 0.01); those with IMH were attenuated further (p < 0.01). Remote myocardial strain was similar across groups at all time-points (p > 0.2). Infarct transmural extent did not correlate with strain (p > 0.05 at each time point). In multivariable logistic regression, MO and IMH were the only significant independent predictors of attenuated 90-day infarct zone strain (p = 0.004, p = 0.011, respectively).

CONCLUSIONS

Strain improves within the infarct zone overall following reperfusion with or without MO or IMH. Mid-myocardial and endocardial infarct contractility is diminished in the presence of MO, and further in the presence of IMH. MO and IMH are greater independent predictors of infarct zone contractile recovery than infarct volume or transmural extent.

A novel echocardiographic method as an indicator of endothelial dysfunction in patients with coronary slow flow

BACKGROUND

To improve clinical outcomes, noninvasive imaging modalities have been proposed to measure and monitor atherosclerosis. Endothelial dysfunction is considered the first stage in the development of atherosclerosis. Brachial artery flow-mediated dilatation (FMD) has been impaired in patients with coronary slow flow (CSF). Recently, color M-mode derived propagation velocity of descending thoracic aorta (aortic propagation velocity-AVP) was shown to be an ultrasonographic marker for atherosclerosis.

AIM

To assess endothelial function in patients with CSF and the correlation of AVP with FMD.

MATERIALS AND METHODS

FMD and AVP were measured in 90 patients with CSF and 39 patients having normal coronary arteries (NCA) detected by coronary angiography.

RESULTS

Compared to patients with normal coronary arteries patients having CSF had significantly lower AVP (39.1±8.4 vs. 53.7±12.7 cm/s, p < 0.001) and FMD (5.6±3.2 vs. 17.6±4.4 %, p < 0.001) measurements. There were significant correlations between AVP and FMD (r = 0.524, p < 0.001).

CONCLUSIONS

Transthoracic echocardiographic determination of color M-mode propagation velocity of descending aorta is a simple practical method and correlates well with coronary slow flow and brachial endothelial function.

Myocardial 'no-reflow' prevention

Despite achievement of optimal epicardial coronary flow in the majority of patients treated for ST-segment elevation myocardial infarction (STEMI) by primary percutaneous coronary intervention (PPCI), myocardial no-reflow is a common phenomenon occurring in 5 to 50% of patients. The no-reflow phenomenon is a predictor of infarct size and an independent predictor of mortality both in the short and long term. Prevention of no-reflow is therefore a crucial step in improving prognosis of patients with STEMI. Several strategies including pharmacological and mechanical ones have been developed to improve microvascular perfusion in the setting of a myocardial infarction. Prevention starts by conservation of the microvascular reserve especially in patients at high risk of acute coronary syndromes such as diabetes patients. Optimal glycaemic control and the use of statins have been shown to reduce no-reflow in this context. Reducing ischaemic time by shortening door to balloon times, administration of intracoronary GP IIb/IIIa antagonists during PPCI and the use of manual aspiration thrombectomy have been shown to result in better myocardial perfusion and improved clinical outcome in major trials. In this review we discuss some of these major trials and studies of other therapeutic options that aim to prevent the no-reflow phenomenon.

Myocardial no-reflow treatment

No-reflow phenomenon is a consequence of percutaneous coronary intervention (PCI) which arises most of the time in the setting of myocardial infarction, but can be also the consequence of PCI in stable angina patients (rotatablator ablation technique or angioplasty in saphenous vein grafts). In this review, we summarize two ways of treating the no-reflow according to the current literature. First through the pharmacological approach where several compounds have been assessed like adenosine, nitroprusside, verapamil, nicorandil, dipyridamole, epinephrine or cyclosporine. Second through the mechanical approach where few strategies have been examined like intra-aortic balloon pumping or postconditioning. Finally, we provide an algorithm for treating a no-reflow even though no studies showed a beneficial effect in terms of clinical endpoints.

Incidence and outcomes of no-reflow phenomenon during percutaneous coronary intervention among patients with acute myocardial infarction

Previous studies describing the no-reflow phenomenon in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) were largely confined to single-center studies or small registries. To better characterize the incidence, predictors, and outcomes of the no-reflow phenomenon in a large contemporary population, we analyzed patients with AMI who were undergoing PCI of native coronary artery stenoses in the CathPCI Registry from January 1, 2004 through September 5, 2008 (n = 291,380). The angiographic no-reflow phenomenon was site reported using a standardized definition. No-reflow developed in 2.3% of the patients with AMI (n = 6,553) during PCI. Older age, ST-segment elevation AMI, prolonged interval from symptom onset to admission, and cardiogenic shock were clinical variables independently associated with the development of no-reflow (p <0.001). The angiographic factors independently associated with no-reflow included longer lesion length, higher risk class C lesions, bifurcation lesions, and impaired preprocedure Thrombolysis In Myocardial Infarction flow (p <0.001). No-reflow was associated with greater in-hospital mortality (12.6% vs 3.8%, adjusted odds ratio 2.20, 95% confidence interval 1.97 to 2.47, p <0.001) and unsuccessful lesion outcome (29.7% vs 6.6%, adjusted odds ratio 4.70, 95% confidence interval 4.28 to 5.17, p <0.001) compared to patients without no-reflow. In conclusion, the development of no-reflow, although relatively uncommon during PCI for AMI, is associated with adverse clinical outcomes. Upfront strategies to reduce the incidence of no-reflow could be considered for high-risk patients to improve outcomes.

CMR of microvascular obstruction and hemorrhage in myocardial infarction

Microvascular obstruction (MO) or no-reflow phenomenon is an established complication of coronary reperfusion therapy for acute myocardial infarction. It is increasingly recognized as a poor prognostic indicator and marker of subsequent adverse LV remodeling. Although MO can be assessed using various imaging modalities including electrocardiography, myocardial contrast echocardiography, nuclear scintigraphy, and coronary angiography, evaluation by cardiovascular magnetic resonance (CMR) is particularly useful in enhancing its detection, diagnosis, and quantification, as well as following its subsequent effects on infarct evolution and healing. MO assessment has become a routine component of the CMR evaluation of acute myocardial infarction and will increasingly play a role in clinical trials of adjunctive reperfusion agents and strategies. This review will summarize the pathophysiology of MO, current CMR approaches to diagnosis, clinical implications, and future directions needed for improving our understanding of this common clinical problem.

Pathophysiology of coronary thrombus formation and adverse consequences of thrombus during PCI

Atherosclerosis is a systemic vascular pathology that is preceded by endothelial dysfunction. Vascular inflammation "fuels" atherosclerosis and creates the milieu for episodes of intravascular thromboses. Thrombotic events in the coronary vasculature may lead to asymptomatic progression of atherosclerosis or could manifest as acute coronary syndromes or even sudden cardiac death. Thrombus encountered in the setting of acute coronary syndromes has been correlated with acute complications during percutaneous coronary interventions such as no-reflow, acute coronary occlusion and long term complications such as stent thrombus. This article reviews the pathophysiology of coronary thrombogenesis and explores the complications associated with thrombus during coronary interventions.

Early statin treatment prior to primary PCI for acute myocardial infarction: REPERATOR, a randomized placebo-controlled pilot trial

OBJECTIVE

The aim of this pilot study was to determine whether early atorvastatin treatment will reduce left ventricle (LV) remodeling, infarct size, and improve microvascular perfusion.

BACKGROUND

In animal studies, early statin therapy reduces reperfusion injury after a percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

METHODS

Forty-two consecutive patients (82% male, mean age 61.2 ± 9.8) who underwent a primary PCI for a first ST-elevated AMI were randomized for pretreatment with atorvastatin 80 mg (n = 20) or placebo (n = 22) and continued with the same dosage daily for 1 week. All patients received atorvastatin 80 mg once daily 7 days after primary PCI. The LV function and infarct size were measured by magnetic resonance imaging within 1 day, at 1 week, and 3 months follow up. The primary endpoint was the end-systolic volume index (ESVI) at 3 months. Secondary endpoints were global LV function measurements, myocardial infarct size, biochemical cardiac markers, TIMI flow, and ST-T elevation resolution.

RESULTS

ESVI 3 months after AMI was 25.1 mL/m(2) in the atorvastatin arm and 25.0 mL/m(2) in the placebo arm (P = 0.74). The differences in change from baseline to 3 months follow up in global LV function and myocardial infarct size did not differ between both treatment arms. Furthermore, biochemical markers, TIMI flow, and ST-T elevation resolution did not differ between atorvastatin and placebo arm.

CONCLUSIONS

In this pilot study, pretreatment with atorvastatin in an acute myocardial infarction does not result in an improved cardiac function, microvascular perfusion, or decreased myocardial infarct size.

[Metabolic issues of ischemia induced myocardial dysfunction]

Myocardial ischemia represents most common cause of necrosis of cardiomyocytes, cardio sclerosis and heart failure. Main clinical manifestation of myocardial ischemia is systolic and/or diastolic dysfunction. It has been shown, that local disturbance of myocardial contractility is not always determined by cell necrosis and cardio sclerosis, as improvement of coronary perfusion may lead to restoration of contractile function of myocardium. Present review outlines aspects of phenomenon of ischemic preconditioning, hibernation and myocardial stunning (so called new ischemic syndromes) that are suggested to be determinants of ischemia induced myocardial dysfunction. No-reflow (Less known type of myocardial stunning) is considered also. However, further studies of molecular mechanisms of ischemic syndromes are necessary for development of new methods of protection of myocardium against ischemic or reperfusion injury.

Persistent coronary no flow after wire insertion is an early and readily available mortality risk factor despite successful mechanical intervention in acute myocardial infarction: a pooled analysis from the STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) trials

OBJECTIVES

These studies sought to investigate the impact on mortality of coronary flow after passage of the wire through the culprit vessel in patients with ST-segment elevation myocardial infarction (STEMI) undergoing mechanical reperfusion.

BACKGROUND

Reduced spontaneous coronary flow before percutaneous coronary intervention influences mortality in patients with STEMI. Response to vessel wiring in patients with an occluded coronary artery before intervention might further discriminate outcomes irrespective of pre- and post-intervention coronary flow.

METHODS

Data from the STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) trials were pooled: of 919 index procedures, 902 films (98%) were technically adequate for core laboratory TIMI (Thrombolysis In Myocardial Infarction) flow determination.

RESULTS

TIMI flow grade 0 was present before percutaneous coronary intervention in 59% of infarct vessels, TIMI flow grade 1 to 2 was found in 21%, whereas the remainder of infarct arteries presented with TIMI flow grade 3. In 49% of patients who showed persistent TIMI flow grade 0 after wire insertion (AWI), mortality was higher at 30 days (5.3%) and 1 year (9.4%) compared with patients in whom TIMI flow grade before percutaneous coronary intervention was either >0 (0.8%; p < 0.003 and 3.6%, p < 0.008) or improved from 0 AWI (1.5%, p < 0.04 and 3.6%, p < 0.02). After correcting for multiple imbalances, including baseline and final flow, persistent TIMI flow grade 0 AWI remained associated at 30 days to 2-fold (risk ratio [RR]: 2.1, 95% confidence interval [CI]: 1.08 to 5.00; p = 0.038) and at 1 year to almost 3-fold increases of mortality (RR: 2.7, 95% CI: 1.3 to 5.6; p = 0.008).

CONCLUSIONS

STEMI patients displaying persistent no-flow AWI have a lower survival rate despite an apparently successful mechanical intervention. As an early marker for high residual mortality risk, persistent no-flow AWI may qualify STEMI patients for dedicated pharmacomechanical treatment strategies.

High admission levels of γ-glutamyltransferase predict poor myocardial perfusion after primary percutaneous intervention

OBJECTIVE

This retrospective study aimed to investigate the relationship between admission levels of serum y-glutamyltransferase and poor myocardial perfusion after primary percutaneous coronary intervention in patients with acute myocardial infarction.

INTRODUCTION

Reperfusion injury caused by free radical release and increased oxidative stress is responsible for the pathophysiology of the no-reflow phenomenon in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention. Serum γ-glutamyltransferase is an established marker of increased oxidative stress.

METHODS

The study population consisted of 80 patients (64 men and 16 women, mean age = 67.5 + 6.6 years) with thrombolysis in myocardial infarction 0/1 flow pre-procedurally. The patients were divided into two groups according to thrombolysis in myocardial perfusion grades that were assessed immediately following primary percutaneous coronary intervention. The two groups (group 1 and group 2) each consisted of 40 patients with thrombolysis in myocardial perfusion grades 0-1 and thrombolysis in myocardial perfusion grades 2-3, respectively.

RESULTS

Admission pain to balloon time, γ-glutamyltransferase and creatine kinase-MB isoenzyme levels of group 1 patients were significantly higher than those of group 2 patients. Pain to balloon time, γ-glutamyltransferase, peak creatine kinase-MB isoenzyme, low left ventricular ejection fraction and poor pre-procedural thrombolysis in myocardial infarction grade were significantly associated with poor myocardial perfusion by univariate analysis. However, only pain to balloon time and γ-glutamyltransferase levels showed a significant independent association with poor myocardial perfusion by backward logistic regression analysis. Adjusted odds ratios were calculated as 4.92 for pain to balloon time and 1.13 for γ-glutamyltransferase.

CONCLUSION

High admission γ-glutamyltransferase levels are associated with poor myocardial perfusion in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention, particularly in patients with prolonged pain to balloon time.

Coronary slow flow and acute coronary syndrome in a patient with spinal cord injury

We report the case of a 55-year-old man who presented with acute coronary syndrome due to coronary slow flow after spinal cord injury. Data regarding the causes and clinical manifestations of coronary slow flow are inconclusive, but the autonomic nervous system is believed to be at least a contributing factor. The predominant vagal activity causes vasodilation and hemostasis, which can lead to acute coronary syndrome. We hereby call attention to hyperactive parasympathetic tonicity, which can lead to coronary slow flow and acute coronary syndrome in acute spinal cord injury patients.