Coronary Microcirculation In Patients Research Articles

Atorvastatin vs Rosuvastatin in the Prevention of Cardiovascular Events: A Systematic Review

The main objective of this study is to compare any differences in the clinical response to rosuvastatin and atorvastatin in patients with cardiovascular disease. PubMed, SCOPUS, Web of Science, Science Direct, and Clinical Key were systematically searched for relevant literature. Rayyan QRCI was employed throughout this comprehensive process. We included eleven studies with a total of 6168 patients; 3231 (52.4%) patients received Atorvastatin, and 2937 (47.6%) received Rosuvastatin. Regarding ACS patients, Rosuvastatin outperformed Atorvastatin in improving laboratory indices and inflammatory markers and lowering LDL. In STEMI patients undergoing PCI, Atorvastatin was linked to less dysfunctional coronary circulation, better coronary microcirculation in patients with STEMI having primary PCI, and may enhance microvascular coronary perfusion immediately following PCI more effectively than a high-dose rosuvastatin preloading. The one study included patients undergoing CABG and did not find any differences between Atorvastatin and Rosuvastatin in preventing post-CABG atrial fibrillation (AF). These results suggest that when developing treatment plans for patients with cardiovascular disease, physicians may be able to combine atorvastatin with rosuvastatin. Cost considerations, tolerability, and patient-specific characteristics should all be taken into account during the decision-making process.

Comprehensive invasive evaluation of coronary microcirculation in patients with Takotsubo syndrome

Background and aimsThe etiology and pathophysiology of Takotsubo syndrome (TTS) remain a matter of debate. In murine models of coronary microvascular dysfunction (CMD), abnormalities in myocardial perfusion led to the development of TTS. Importantly, TTS was reversible when normal perfusion was restored. However, in clinical practice, the assessment of coronary microcirculation in patients with TTS has primarily relied on non-invasive or indirect, angiography-derived methods. Methods and ResultsFor the first time, we performed invasive microcirculatory assessment, by both validated techniques currently available in the catheterization laboratory, namely intracoronary bolus and continuous thermodilution, in patients with TTS, upon hospital admission and at short term follow-up. Our findings demonstrate that CMD was consistently present in all patients upon hospital admission, as assessed by both techniques. At a median follow-up of 3 months, after the recovery of left ventricular ejection fraction, two third of patients no longer exhibited CMD. ConclusionsThese findings support the hypothesis that an acute and transient worsening in coronary microvascular function plays a pivotal role in the pathophysiology of TTS.

Left ventricular function and coronary microcirculation in patients with mild reduced ejection fraction after STEMI

BackgroundThe characteristics of heart failure (HF) with mildly reduced ejection fraction (EF) (HFmrEF) overlap with those of HF with reduced EF (HFrEF) and HF with preserved EF (HFpEF) and need to be further explored. This study aimed to evaluate left ventricular (LV) function and coronary microcirculation in patients with mildly reduced ejection fraction after acute ST-segment elevation myocardial infarction (STEMI).MethodsWe enrolled 119 patients with STEMI who had undergone speckle tracking imaging and myocardial contrast echocardiography during hospitalization from June 2016 to June 2021. They were classified into normal, HFmrEF, and HFrEF groups according to their left ventricular EF (LVEF): ≥ 50%, 40–50%, and ≤ 40%, respectively. The data of the HFmrEF group were analyzed and compared with those of the normal and HFrEF groups.ResultsHFmrEF was observed in 32 patients (26.9%), HFrEF in 17 (14.3%), and normal LVEF in 70 patients (58.8%). The mean global longitudinal strain (GLS) of all patients was − 11.9 ± 3.8%. The GLS of HFmrEF patients was not significantly different from that of the HFrEF group (− 9.9 ± 2.5% and − 8.0 ± 2.3%, respectively, P = 0.052), but they were both lower than that of the normal group (− 13.8% ± 3.5%, P < 0.001). The HFmrEF group exhibited significantly poorer myocardial perfusion index (1.24 ± 0.33) than the normal group (1.08 ± 0.14, P = 0.005) but displayed no significant difference from the HFrEF group (1.18 ± 0.19, P = 0.486). Moreover, a significant difference in the incidence of regional wall motion (WM) abnormalities in the three groups was observed (P = 0.009), and the WM score index of patients with HFmrEF was 1.76 ± 0.30, similar to that of patients with HFrEF (1.81 ± 0.43, P = 0.618), but poorer than that in the normal group (1.33 ± 0.25, P < 0.001).ConclusionsGLS is a more sensitive tool than LVEF for detecting LV systolic dysfunction. The LV systolic function, coronary microcirculation, and WM in patients with HFmrEF was poorer than that of patients with normal LVEF, but comparable to that in patients with HFrEF. Patients with HFmrEF after STEMI require more attention and appropriate management.

The role of coronary flow reserve (CFR) and fractional flow reserve (FFR) in acute coronary syndrome - systematic review

The methods used to appreciate the degree of coronary stenosis such as CFR and FFR, come to complement the coronary angiography and help the interventional physician during PCI. Furthermore, CFR and FFR measured immediately after reperfusion, in patients with ACS, may act as a prognosis factor for myocardial infarction.Changes in coronary microcirculation in patients with ACS and NSTEMI correlate to the degree and extent of tissue lysis processes.So far, there are few data revealing the degree of microvascular bed injury and vasodilator capacity in patients with acute myocardial infarction. In this article, we will refer to some studies in the field.

Effects of Ticagrelor and Clopidogrel on Coronary Microcirculation in Patients with Acute Myocardial Infarction.

IntroductionClopidogrel has been demonstrated to be effective in improving coronary microcirculation (CM) among patients with ST-elevation myocardial infarction (STEMI) treated with fibrinolytics. Ticagrelor is a more potent adenosine diphosphate (ADP) receptor blocker proven to be superior to clopidogrel among patients with acute coronary syndromes. The present study aimed to compare the effects of ticagrelor and clopidogrel on CM in patients with STEMI treated with fibrinolytics.MethodsThe present study prospectively included 48 patients participating in the TREAT trial, which randomly assigned patients with STEMI undergoing fibrinolysis to ticagrelor versus clopidogrel. The primary endpoint of this study was the evaluation of the CM using the global myocardial perfusion score index (global MPSI) obtained by myocardial contrast echocardiography (MCE). Platelet aggregation to ADP was evaluated by Multiplate® and expressed as area under the curve (AUC).ResultsThe global MPSI demonstrated no differences between the groups [mean 1.4 (1.2–1.5) in the ticagrelor group and 1.2 (1.2–1.5) in the clopidogrel group (p = 0.41)]. Platelet aggregability was lower in the ticagrelor group (18.1 ± 9.7 AUC), compared to the clopidogrel group (26.1 ± 12.5 AUC, p = 0.01).ConclusionWe found no improvement in coronary microcirculation with ticagrelor compared to clopidogrel among patients with STEMI treated with fibrinolytics, despite the fact that platelet aggregation to ADP was lower with ticagrelor.Clinical Trials RegistrationNCT03104062.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12325-022-02061-0.

Impact of transcatheter aortic valve implantation on coronary flow reserve by transthoracic Doppler echocardiography 1-year after the intervention in severe aortic stenosis patients

Abstract Background Coronary flow reserve (CFR) which is one of indexes reflecting coronary microcirculation in patients without significant epicardial coronary lesions can be impaired in patients with severe aortic stenosis (AS). It has been shown that CFR is an independent predictor for future cardiovascular events in AS patients. Transcatheter aortic valve implantation (TAVI) has rapidly become widespread and is becoming the standard treatment for severe AS. This procedure may have a good effect on CFR due to reduction of severe afterload in patients with severe AS. Although the recent reports evaluated change in CFR immediately and 6 months after TAVI, it has not been evaluated whether impaired CFR improves 1-year after TAVI in AS patients with preserved left ventricular ejection fraction (LVEF). Purpose The purpose of the present study was to investigate whether impaired CFR improves 1-year after TAVI in severe AS patients with preserved LVEF. Methods The study population consists of consecutive 105 patients with severe AS undergoing TAVI. Exclusion criteria were atrial fibrillation, old myocardial infarction, history of coronary artery bypass grafting, significant lesions in the left anterior descending artery (LAD), moderate or severe mitral valve disease, history of valve replacement, LVEF &amp;lt;50% and preoperative CFR &amp;gt;2.2. CFR was obtained from coronary flow velocity by transthoracic echocardiography at rest and maximal hyperemia in LAD before, immediately and 1-year after TAVI. We compared CFR between before and after TAVI in the study patients who did not meet the exclusion criteria. Results After exclusion of 76 patients who met the exclusion criteria, the final study patients consist of 29 patients (8 male, 84.9±5.2 years). There was no significant difference in LVEF (61.3±3.4% vs 61.6±4.4%, P=0.667) and LV end-diastolic volume (LVEDVI; 58.2±9.2 mL/m2 vs 55.8±9.0 mL/m2, P=0.089) between before and immediately after TAVI. LVEF (61.0±2.8%, P=0.721) and LVEDVI (58.0±9.1 mL/m2, P=0.949) 1-year after TAVI were similar to those before TAVI. There was no significant difference in coronary flow velocity at rest between before and immediately after TAVI (27.4±8.9 vs 24.4±7.0 cm/s, P=0.051) and between before and 1-year after TAVI (25.9±8.3 cm/s, P=0.396). Coronary flow velocity at maximal hyperemia 1-year after TAVI significantly increased compared with that before TAVI (from 48.8±13.9 to 67.9±21.0 cm/s, P&amp;lt;0.001) while there was no significant difference between before and immediately after TAVI (52.0±12.0 cm/s, P=0.186). Impaired CFR before TAVI (1.82±0.28) increased immediately (2.03±0.39, P=0.009) and 1-year after TAVI (2.69±0.57, P&amp;lt;0.001). Conclusions The present results suggest that impaired CFR in patients with preserved LVEF improves 1-year after TAVI. TAVI may have a good effect on CFR in severe AS patients with preserved LVEF. Funding Acknowledgement Type of funding sources: None.

Coronary flow reserve and microcirculatory resistance in patients with coronary tortuosity and without atherosclerosis.

ObjectiveCoronary tortuosity may affect epicardial coronary arterial blood flow. This study aimed to investigate the effect of coronary tortuosity on coronary flow reserve and the coronary microcirculation in patients without apparent coronary atherosclerosis.MethodsProspective patients (n = 8, 3 men, mean age: 58 ± 6.0 years) with coronary tortuosity and without apparent coronary atherosclerosis were enrolled. Coronary tortuosity was defined by the finding of ≥three bends (defined as a ≥45° change in vessel direction) along the main trunk of the left anterior descending artery or left circumflex artery. Coronary flow reserve and the index of microcirculatory resistance were measured by the thermodilution technique.ResultsA total of eight coronary arteries with coronary tortuosity were analyzed. The mean fractional flow reserve was 0.98 ± 0.007. The mean coronary flow reserve was 1.5 ± 0.3, which is much lower than that in the normal coronary artery as reported in the literature. The mean index of microcirculatory resistance was 26.7 ± 2.3, which is much higher than that in the normal coronary artery.ConclusionsCoronary tortuosity is associated with decreased coronary flow reserve and an increased index of microcirculatory resistance.Trial registration: This study is registered at the Chinese Clinical Trial Registry, NCT No: ChiCTR2000033671

Link between von Willebrand factor multimers, relapses and coronary microcirculation in patients with thrombotic thrombocytopenic purpura in remission

IntroductionADAMTS13 deficiency results in unusually large von Willebrand factor (ULVWF) multimers in the circulation and a higher risk of microthrombi due to high shear stress. In patients treated for acquired thrombotic thrombocytopenic purpura (TTP), a persistently severe ADAMTS13 deficiency (<10%) in remission is associated with more relapses. A reduced plasma ADAMTS13 activity and increased VWF levels are associated with a higher risk of myocardial infarction. Assessing coronary flow reserve (CFR) enables a better cardiovascular risk stratification: a lower CFR correlates inversely with cardiovascular risk. The aim of the study was to establish whether patients with TTP in remission have an impaired coronary microcirculation, in terms of a lower CFR, and whether there is any correlation between ADAMTS13 activity, the presence of ULVWF multimers, and the occurrence of relapses. MethodsThe clinical information and hemostatic parameters of 24 patients with TTP in remission managed at our center were analyzed. The CFR was assessed in a subgroup of the TTP patients and compared with a control group consisting of 50 healthy volunteers. ResultsThe CFR was statistically lower in patients in remission of TTP than in controls, but there were no differences between TTP patients with normal and lower CFR. The occurrence of relapses correlated with the presence of ULVWF multimers and with a residual ADAMTS13 activity. ConclusionsWhen compared with healthy controls, TTP patients in remission have an impaired coronary microcirculation and the occurrence of relapses in the former reveal the presence of ULVWF multimers.

GW28-e0828 Comparative Study of Thrombolysis with PCI and Primary PCI on Coronary Microcirculation in patients with Anterior STEMI

Comparing thrombolysis combined with PCI and primary PCI on coronary microcirculation in patients with anterior ST-segment elevation myocardial infarction. From March 2015 to December 2016, all anterior STEMI patients within 24 hours from symptom onset in Cardiology Department of our hospital were

Relation Between Neutrophil-to-Lymphocyte Ratio and Index of Microcirculatory Resistance in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

The neutrophil-to-lymphocyte ratio (NLR) has been proved as a reliable inflammatory marker for the atherosclerotic process and as a predictor for clinical outcomes in patients with various cardiovascular diseases. A recent study reported that elevated NLR is associated with impaired myocardial perfusion in patients with ST-segment elevation myocardial infarction (STEMI). We investigated whether NLR is associated with coronary microcirculation as assessed by the index of microcirculatory resistance (IMR) in patients with STEMI who had undergone primary percutaneous coronary intervention (PCI). A total of 123 patients with STEMI who underwent successful primary PCI were enrolled in this study. NLR was obtained on admission, and patients were divided into 3 groups by NLR tertile. IMR was measured using an intracoronary thermodilution-derived method immediately after index PCI. Symptom onset-to-balloon time was significantly longer (p=0.005), and IMR was significantly higher in the high NLR group than that in the low and intermediate groups (21.94 ± 12.87 vs 23.22 ± 12.73 vs 32.95 ± 20.60, p= 0.003). Furthermore, in multiple linear regression analysis, NLR showed an independent positive correlation with IMR (r= 0.205, p= 0.009). In conclusion, NLR has shown positive correlation with IMR, whereas negative association with infarct-related artery patency in patients with STEMI who underwent primary PCI. Therefore, NLR at admission could reflect myocardial damage and the status of coronary microcirculation in patients with STEMI (ClinicalTrials.gov number, NCT02828137).

Noninvasive study of coronary microcirculation response to a cold pressor test

The aims of this study were to noninvasively (i) assess the coronary microcirculation changes in response to a cold pressor test (CPT) in control subjects, nondiabetic obese patients and patients with type 2 diabetes and (ii) investigate the response of the coronary microcirculation in patients with diabetes according to the presence or the absence of silent myocardial ischaemia (SMI), asymptomatic coronary stenosis (CS) and left ventricle hypertrophy (LVH). The mean left anterior descending coronary flow velocity (mCFV) was measured using transthoracic Doppler before and after a CPT in 16 control subjects, 11 obese and 66 asymptomatic diabetic patients with a high cardiovascular risk. Patients with diabetes were screened for SMI using stress myocardial scintigraphy and/or echocardiography. A coronary angiography was performed in those with SMI. At baseline, pressure-rate product (PRP) was correlated with mCFV (r = 0.23; P < 0.05) and left ventricle mass (r = 0.26; P < 0.05) in the whole population. Changes in PRP and mCFV during CPT were correlated with controls (r = 0.58, P < 0.05), obese (r = 0.75, P < 0.01) and diabetic patients without CS (r = 0.56, P < 0.0001) or without LVH (r = 0.63, P < 0.05) but not in diabetic patients with CS or with LVH. In patients with diabetes, SMI was associated with mCFV changes, independent of other parameters (P < 0.05). Transthoracic coronary Doppler allows noninvasive study of changes in the coronary microcirculation during CPT. In asymptomatic patients with type 2 diabetes, this method showed that SMI was associated with mCFV changes during CPT and the presence of CS or LVH was associated with a mismatch between coronary microcirculation and myocardial oxygen demand.

Impact of Admission Anemia on Coronary Microcirculation and Clinical Outcomes in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention.

Microvascular dysfunction after primary percutaneous coronary intervention (PCI) augments myocardial damage and prognosis in acute myocardial infarction. However, the relationship between baseline anemia and coronary microcirculation in patients with ST-segment elevation myocardial infarction (STEMI) remains unclear. We performed primary PCI in 337 consecutive patients with STEMI. Anemia was defined as a hemoglobin level < 13 g/dL in men and < 12 g/dL in women. Admission anemia was present in 17.5% of the patients enrolled. Data on epicardial coronary flow, STsegment resolution (STR) on electrocardiography, myocardial injury, and the incidence of adverse cardiac events defined as cardiac death or hospitalization for congestive heart failure were analyzed. The median follow-up period was 54.8 months. Despite comparable epicardial coronary flow, the rate of STR ≥ 50% was lower in anemic patients compared with non-anemic patients (55.9% versus 71.2%, P = 0.02). On multivariate logistic regression analysis, baseline anemia was an independent negative predictor of STR ≥ 50% (odds ratio, 0.53; 95% confidence interval: 0.31-0.92, P = 0.03). Moreover, anemic patients had higher maximum creatine kinase levels normalized for body surface area (2,215 ± 1,318 IU/L/m(2) versus 1,797 ± 1,199 IU/L/m(2), P = 0.047). Anemia remained an independent significant predictor of adverse events on multivariate Cox proportional hazard analysis (hazard ratio, 2.34; 95% confidence interval: 1.01-5.64, P = 0.048). In conclusion, admission anemia was related to microcirculatory dysfunction and poor prognosis in patients with STEMI. The decreased oxygen delivery might exacerbate microvascular function.

Abstract 13697: Glucagon-like Peptide-1 Analogue Liraglutide Does Not Improve Microvascular Myocardial Function in Patients With Type 2 Diabetes - a Randomized, Single-blinded Cross Over Trial

Background: Impaired coronary microcirculation is associated with a poor prognosis in patients with type 2 diabetes. In the absence of stenosis of major coronary arteries, coronary flow reserve (CFR) reflects coronary microcirculation. Studies have shown beneficial effects of glucagon-like peptide-1 (GLP-1) on the cardiovascular system. The aim of the study was to explore the short-term effect of GLP-1 treatment on coronary microcirculation estimated by CFR in patients with type 2 diabetes. Methods: Twenty patients with type 2 diabetes and no history of coronary artery disease were treated with the GLP-1 analogue Liraglutide for 10 weeks, in a randomized single-blinded crossover setup. The effect of GLP-1 on coronary microcirculation was evaluated using non-invasive trans-thoracic Doppler-flow echocardiography during dipyridamole induced stress. Data were analysed as two-sample t-test after ensuring no carry over effect. Results: A total of 20 patients (15 male; mean age 57 ± 9; mean BMI 33.1 ± 4.4, mean baseline CFR 2.35 ± 0.45) completed full protocol. There was a small increase in CFR following GLP-1 treatment (change 0.18, CI95% [-0.01; 0.36], p=0.06) but with no difference in effect compared with the no treatment group (0.16, CI95% [-0.08; 0.40], p=0.18). GLP-1 significantly reduced glycated haemoglobin (-10.1 mmol/mol CI95% [-13.9; -6.4], p=&lt;0.001) systolic blood pressure (-10 mmHg CI95% [-17; -3], p=0.01) and weight (-1.9 kg CI95% [-3.6; -0.2], p=0.03). Conclusion: Despite a significant weight-loss, reduction in HbA1c and systolic blood pressure, we did not find a significant improvement in coronary microcirculation after 10 weeks treatment with GLP-1. In our short-term treatment study, we therefore conclude that the GLP-1 analogue Liraglutide does not improve coronary microcirculation in patients with type 2 diabetes. Further long-term studies are needed to explore mechanisms to improve coronary microcirculation in patients with type 2 diabetes.

SCINTIGRAPHIC ESTIMATION OF THE SYMPATHETIC INNERVATION OF THE HEART AND MYOCARDIAL PERFUSION IN PATIENTS WITH ATRIAL FIBRILLATION

Aim. The aim of the study was to scintigraphically evaluate the condition of sympathetic innervation of myocardium and coronary microcirculation in patients with atrial fibrillation (AF). Material and methods. Totally 40 patients included with CHD II-III functional class and AH III stage. Of those: 15 patients — with paroxysmal AF (PAF), 15 — with long-lasting persistent AF (LPAF) and 10 patients — without any signs of AF. To evaluate the sympathetic activity of the myocardium all patients underwent scintigraphy with 123I-metaiodbenzylguanidine (123I-MIBG). With planary study of myocardium investigation with 123I-MIBG we assessed regionary sympathetic activity by the relation of “Heart/ Mediastinum” (H/M) and speed of indicator washout. Also all participants underwent myocardial scintigraphy with 99mTc-MIBG to measure coronary microcirculation. Results. Analysis of the data showed that patients with PAF and LPAF the relation of H/M at early and delayed scintigrammes was significantly lower comparing to the same value in the patients without AF (1,57±0,15, 1,54±0,18 vs. 1,82±0,12 on early scintigrammes and 1,47±0,15, 1,46±0,16 vs. 1,83±0,13 on delayed, with p<0,05). Also in PAF and LPAF was significantly higher the velocity of indicator excretion comparing to the group of patients without AF (31,2%±11,5%, 29,4%±10,5% vs. 17,5%±10,3%, resp., p<0,05). By the evaluation of regional sympathetic activity in patients with LPAF the filling defect of 123I-MIBG on early and delayed scintigrammes was significantly higher than in groups with PAF and without AF. In evaluation of coronary microcirculation there were no any significant differences of the perfusion defect among the groups studied. Conclusion. The study showed that in patients with AF there are the most prominent changes in functional conditions of myocardial sympathetic system comparing to the group without AF. At the same time AF does not lead to significant influence on myocardial flow, and the most significant disorders of regional sympathetic activity are visible in patients with long persistent AF.

AB0797 Impairment of coronary microcirculation in patients with diffuse systemic sclerosis

BackgroundAn association between systemic autoimmune diseases (SADs) and atherosclerosis has been described in many connective tissue diseases, and is known to lead to increased cardiovascular (CV) morbidity and mortality. Systemic...

Vasodilatory Capacity of the Coronary Microcirculation is Preserved in Selected Patients With Non–ST-Segment–Elevation Myocardial Infarction

The use of fractional flow reserve in patients with non-ST-segment-elevation myocardial infarction (NSTEMI) is a controversial issue. We undertook a study to assess the vasodilatory capacity of the coronary microcirculation in patients with NSTEMI when compared with a model of preserved microcirculation (stable angina [SA] cohort: culprit and nonculprit vessel) and acute microcirculatory dysfunction (ST-segment-elevation myocardial infarction [STEMI] cohort). We hypothesized that the vasodilatory response of the microcirculation would be preserved in NSTEMI. A total of 140 patients undergoing single vessel percutaneous coronary intervention were included: 50 stable angina, 50 NSTEMI, and 40 STEMI. The index of microvascular resistance (IMR), fractional flow reserve, and coronary flow reserve were measured before stenting in the culprit vessel and in an angiographically normal nonculprit vessel in patients with SA. The resistive reserve ratio, a measure of the vasodilatory capacity of the microcirculation and calculated using the equation: baseline resistance index (TmnBase×PaBase[PdBase-Pw/PaBase-Pw])-IMR/IMR, where TmnBase referred to nonhyperemic transit time; PaBase and PdBase, the nonhyperemic aortic and distal coronary pressures, respectively; and Pw referred to the coronary wedge pressure, was also measured. Troponin was also measured ≤24 hours after percutaneous coronary intervention. The resistive reserve ratio was significantly lower in the STEMI patients compared with the stable angina patients both culprit and nonculprit vessel (STEMI, 1.7 versus SA culprit, 2.8; P≤0.001 and SA nonculprit, 2.9; P<0.0001) and compared with NSTEMI patients (NSTEMI, 2.46; P≤0.001). The resistive reserve ratio was similar in stable angina and NSTEMI patients (P=0.6). IMR was significantly higher pre-PCI in STEMI compared with SA and NSTEMI (IMR STEMI, 36.51 versus IMR NSTEMI, 22.73 [P=0.01] versus IMR SA, 18.26 [P<0.0001]). However, there was no significant difference in IMR pre-PCI between NSTEMI and SA (IMR NSTEMI, 22.73; IMR SA, 18.26 [P=0.1]). The vasodilatory capacity of the microcirculation is preserved in selected patients with NSTEMI. The clinical use of fractional flow reserve in the culprit vessel may be preserved in selected patents with NSTEMI.

Safety and feasibility of high-dose administration of nicorandil before reperfusion therapy in acute myocardial infarction

The efficacy and safety of high-dose nicorandil therapy in acute myocardial infarction (AMI) have not yet been clarified. This is a prospective study including 30 patients who received nicorandil at 0.06 mg/kg/h [standard dose nicorandil (SDN) group] and 32 patients who received a bolus injection of nicorandil 0.2 mg/kg followed by a continuous infusion at 0.2 mg/kg/h [high-dose nicorandil (HDN) group]. The benefits and adverse events were assessed during acute phase and 12-month follow-up period. There were no significant differences between the groups in blood pressure, heart rate or urine volume 2, 6 and 24 h after drug administration, although blood pressure decreased during acute phase. The percentages of patients who required dose reduction or discontinuation of nicorandil were 34.4 and 16.7 % in HDN and SDN groups, respectively (p = 0.11). In HDN group, subgroup analysis revealed that the TIMI frame count (TFC) was significantly lower in patients in whom the treatment was started within 12 h compared to those more than 12 h (17.0 vs. 21.0, p = 0.017) and in patients with baseline WBC elevation compared to those without it (16.5 vs. 22.0, p = 0.029). A TFC of >20 was significantly associated with being in HDN group [odds ratio (OR) 0.27; 95 % confidence interval, CI 0.07-0.89], onset-to-balloon time (OR 1.06; 95 % CI 1.01-1.16), and ∑creatine kinase (OR 7.27; 95 % CI 1.40-57.83). There were no significant differences in incidences of cardiovascular death, rehospitalization, and target lesion revascularization between the groups. HDN therapy may improve coronary microcirculation in patients with AMI.

The effect of acute administration of statins on coronary microcirculation during the pre-revascularization period in patients with myocardial infraction

The beneficial effects of statin pretreatment as well as of staccato reperfusion (SR) on myocardium have been demonstrated in patients undergoing cardiac interventions. In this study, we compared the effects of the acute statin administration prior to percutaneous coronary intervention (PCI) with the effects of staccato or abrupt reperfusion on coronary microcirculation in patients with myocardial infarction (MI). MethodsWe randomly assigned 47 patients who had ST-elevation or non-ST-elevation MI 48 h prior to PCI, into three groups: staccato reperfusion (consisting of 6 periods of 10-s balloon inflation/deflation) plus statin therapy (SRSG), statin therapy plus abrupt reperfusion (SG), and abrupt reperfusion alone (ARG). Myocardial contrast echocardiography (MCE) was performed to assess the blood volume (A), velocity (β) and flow (A × β) of the segments associated with the PCI-treated artery the day following intervention and 30 days after. LV end-diastolic (EDV) and systolic volumes (ESVs), wall motion score index (WMSI) were evaluated. ResultsCompared to ARG, SRSG and SG resulted in a greater improvement in A, β and A × β (F = 20.6, p < 0.001 for A, F = 3.5, p = 0.03 for β and F = 11.3, p < 0.001 for A × β for the overall effect of intervention) as well as a greater decrease of WMSI, EDV and ESV (p < 0.01) one month post-PCI. The changes of all echocardiography markers were greater in SRSG than SG (p < 0.01). The % changes in ESV correlated with the corresponding % changes in MCE indices in SRSG and SG (p < 0.05). ConclusionThe acute statin administration prior to reperfusion either alone or in synergy with staccato reperfusion ameliorates coronary microcirculatory dysfunction in patients with myocardial infarction

Reply to letter to the editor: coronary flow velocity reserve was impaired in chronic hyperhomocysteinemic patients: why?

to the editor: Hyperhomocysteinemia (HHcy) is considered a potentially modifiable risk factor for coronary artery disease (CAD) and atherosclerosis. The possible mechanisms of accelerated CAD in HHcy include endothelial dysfunction and enhanced oxidative stress ([13][1]). However, the precise

Impact of Obstructive Sleep Apnea on Myocardial Tissue Perfusion in Patients With ST-Segment Elevation Myocardial Infarction

Vascular endothelial dysfunction has been recognized as an essential feature of obstructive sleep apnea (OSA). This study was designed to examine the hypothesis that OSA may impair the coronary microcirculation in patients with ST-segment elevation myocardial infarction (STEMI). The present study included 100 patients with a first STEMI who underwent primary percutaneous coronary intervention (PCI) within 12h from onset. Coronary flow velocity at baseline and at maximum hyperemia was measured using a Doppler guidewire following PCI. Total ST-segment elevation was calculated at baseline and 30 min after PCI. All patients underwent polysomnography at 14 days to diagnose OSA. Coronary flow velocity reserve (CFVR) was used for quantitative analysis of myocardial tissue perfusion. Systolic retrograde flow (SRF) and ST-segment resolution (STR) <50% were used as an index of microvascular injury. Forty-eight patients presented with OSA. CFVR was comparable between the 2 groups. The incidence of SRF was higher in OSA patients than in the control patients (6% vs. 31%, P=0.005). Patients with OSA had a higher incidence of STR <50% (31% vs. 60%, P=0.003). Multiple logistic regression showed that OSA was an independent positive predictor of SRF and STR <50% (odds ratio=4.46, P=0.044; odds ratio=3.79, P=0.010). OSA may impair myocardial tissue perfusion following primary PCI.