Myocardial Perfusion In Patients Research Articles

Myocardial perfusion using cardiac magnetic resonance: Evidence of decreased global myocardial perfusion in patients with systemic sclerosis with possible gender differences

Myocardial perfusion using cardiac magnetic resonance: Evidence of decreased global myocardial perfusion in patients with systemic sclerosis with possible gender differences

Abstract 16763: Unchanged Central Aortic Blood Pressure and Increased Myocardial Perfusion in Patients With Stable Coronary Artery Disease Receiving Ivabradine

Background: Treatment of hypertensive patients with beta-blockers reduces heart rate (HR) and increases central blood pressure, implying that the decrease in HR could explain reported increases in cardiovascular risk with beta-blocker. This analysis from a randomized, double-blind study explores whether HR reduction with the I f inhibitor ivabradine had an impact on central blood pressure and coronary perfusion. Methods and results: We included 12 normotensive patients with stable CAD, HR ≥70 bpm (sinus rhythm), and stable background beta-blocker therapy. Patients received ivabradine 7.5 mg bid or matched placebo for two 3-week periods with a crossover design and evaluation by aplanation tonometry. Treatment with ivabradine was associated with a significant reduction in resting HR after 3 weeks versus no change with placebo (-15.8±7.7 versus +0.3±5.8 bpm, p=0.0010). There was no relevant between-group difference in change in central aortic SBP (-4.0±9.6 versus +2.4±12.0 mm Hg, p=0.13) or augmentation index (-0.8±10.0% versus +0.3±7.6%, p=0.87). Treatment with ivabradine was associated with prolongation of diastolic perfusion time by 41% from baseline to 3 weeks (+215.6±105.3 versus -3.0±55.8 ms with placebo, p=0.0005) (Figure) and with a pronounced increase in an index of myocardial viability (Buckberg index, +39.3±27.6% versus -2.5±13.5% with placebo, p=0.0015). There were no safety issues during the study. Conclusion: Heart rate reduction with ivabradine does not modify central aortic blood pressure and is associated with a marked prolongation of diastolic perfusion time and an improvement in myocardial perfusion.

Abstract 13031: A Randomized Trial Comparing the Effects of Ticagrelor versus Clopidogrel on Myocardial Perfusion in Patients With Coronary Artery Disease

Introduction: Ticagrelor is a reversible P2Y12 receptor antagonist used in patients with acute coronary syndrome (ACS). In the PLATO trial, treatment with ticagrelor reduced mortality compared to clopidogrel, to which pleotropic mechanisms may have contributed. In this study, we compared the effects of ticagrelor versus clopidogrel in patients with stable coronary artery disease on myocardial blood flow (MBF) at rest and during intermediate and high dose adenosine infusion. Methods: Patients (n=22) were randomized using a double-blind crossover design to ticagrelor 90 mg orally twice a day for 10 days and clopidogrel 75 mg orally once a day for 10 days, with a washout period of at least 5 days between the treatments. MBF was measured using Rb-82 PET-CT at baseline and at intermediate (80 mcg/kg/min) and high dose adenosine (140 mcg/kg/min). Results: Global MBF was significantly greater with ticagrelor versus clopidogrel at intermediate dose adenosine (1.28±0.55 versus 1.13±0.47, p=0.002), and not different at baseline (0.65±0.19 versus 0.60±0.15, p=0.4254) nor at high dose adenosine (1.64±0.40 versus 1.61±0.19, p=0.5302). In abnormal segments with low MBF reserve (<2.5), MBF was significantly greater with ticagrelor compared to clopidogrel at intermediate and high dose of adenosine (p<0.0001), with no difference at baseline. For segments with high MBF reserve (≥2.5 and < 3.5), segmental MBF was significantly greater with ticagrelor compared to clopidogrel at baseline (p<0.001) and at intermediate adenosine dose (p<0.0001). Conclusions: Global stress MBF was greater with ticagrelor compared to clopidogrel during intermediate dose adenosine infusion. Regional MBF in segments with reduced MBF reserve was greater with ticagrelor compared to clopidogrel during intermediate and high dose adenosine. This suggests that ticagrelor may potentiate adenosine-induced myocardial blood coronary flow increases in patients with stable CAD compared to clopidogrel; an effect that may explain the observed incremental mortality benefit observed with ticagrelor.

Impact of Ivabradine on Central Aortic Blood Pressure and Myocardial Perfusion in Patients With Stable Coronary Artery Disease.

Treatment of hypertensive patients with β-blockers reduces heart rate and decreases central blood pressure less than other antihypertensive drugs, implying that reducing heart rate without altering brachial blood pressure could increase central blood pressure, explaining the increased cardiovascular risk reported with β-blocker. We describe a randomized, double-blind study to explore whether heart rate reduction with the If inhibitor ivabradine had an impact on central blood pressure. We included 12 normotensive patients with stable coronary artery disease, heart rate ≥70 bpm (sinus rhythm), and stable background β-blocker therapy. Patients received ivabradine 7.5 mg BID or matched placebo for two 3-week periods with a crossover design and evaluation by aplanation tonometry. Treatment with ivabradine was associated with a significant reduction in resting heart rate after 3 weeks versus no change with placebo (-15.8±7.7 versus +0.3±5.8 bpm; P=0.0010). There was no relevant between-group difference in change in central aortic systolic blood pressure (-4.0±9.6 versus +2.4±12.0 mm Hg; P=0.13) or augmentation index (-0.8±10.0% versus +0.3±7.6%; P=0.87). Treatment with ivabradine was associated with a modest increase in left ventricular ejection time (+18.5±17.8 versus +2.8±19.3 ms; P=0.074) and a prolongation of diastolic perfusion time (+215.6±105.3 versus -3.0±55.8 ms with placebo; P=0.0005). Consequently, ivabradine induced a pronounced increase in Buckberg index, an index of myocardial viability (+39.3±27.6% versus -2.5±13.5% with placebo; P=0.0015). In conclusion, heart rate reduction with ivabradine does not increase central aortic blood pressure and is associated with a marked prolongation of diastolic perfusion time and an improvement in myocardial perfusion index. URL: https://www.clinicaltrialsregister.eu. Unique identifier: 2011-004779-35.

Effect of Diltiazem on Coronary Artery Flow and Myocardial Perfusion in Patients With Isolated Coronary Artery Ectasia and Either Stable Angina Pectoris or Positive Myocardial Ischemic Stress Test

Isolated coronary artery ectasia (CAE) may be associated with stable or unstable coronary events despite the absence of epicardial coronary stenosis. Impaired coronary flow dynamics and myocardial perfusion have been demonstrated in stable patients with ectatic coronary arteries. We aimed to assess whether epicardial flow and tissue-level perfusion would be improved by diltiazem in myocardial regions subtended by the ectatic coronary arteries in patients with isolated CAE. A total of 60 patients with isolated CAE were identified of 9,780 patients who underwent elective coronary angiography. Patients were randomized to 5mg of intracoronary diltiazem or saline. Coronary blood flow of the microvascular network was assessed using myocardial blush grade (MBG) technique. The thrombolysis in myocardial infarction (TIMI) flow grade and TIMI frame count (TFC) were used to assess epicardial coronary flow. MBG (from 2.4 to 2.6, p= 0.02), TIMI flow grades (from 2.4 to 2.8, p <0.001), and TFC (from 35 to 26, p <0.001) were significantly improved after diltiazem, whereas no significant change was noticed after saline (from 2.4 to 2.4, p= 0.86 for MBG; from 2.3 to 2.3, p= 0.71 for TIMI flow grade; and from 35 to 33, p= 0.43 for TFC). Diltiazem provided amelioration of the altered coronary flow dynamics, which was suggested as the pathophysiological influence of CAE. In conclusion, the favorable effects of the diltiazem on myocardial perfusion were observed at both epicardial and tissue levels.

The Relationship Between Some Complete Blood Count Parameters and Myocardial Perfusion: A Scintigraphic Approach.

Recent studies have shown that there is a relationship between some inflammatory and biochemical markers derived from complete blood count (CBC) such as neutrophil/lymphocyte (N/L) ratio, platelet/lymphocyte (P/L) ratio, platelet distribution width (PDW), red blood cell distribution width (RDW), and coronary artery disease (CAD). The aim of this study was to determine N/L ratio, P/L ratio, PDW values, and RDW values, which are associated with myocardial perfusion in patients diagnosed with CAD. This study included 262 patients (149 with myocardial ischemia/infarction and 113 with normal myocardial perfusion) undergoing myocardial perfusion scintigraphy (MPS) with CBC within 90 days of MPS. Myocardial perfusion parameters such as summed stress score and summed difference score (SDS) were compared with N/L ratio, P/L ratio, PDW values, and RDW values. Neutrophil counts and N/L ratios were significantly higher in patients diagnosed with myocardial ischemia and/or infarct. However, there was no statistically significant relationship between myocardial perfusion abnormalities and P/L ratio, PDW values, and RDW values. This study showed that N/L ratio is related to myocardial ischemia/infarction and correlated to left ventricular ejection fraction (LVEF).

Intracoronary administration of nicorandil during primary percutaneous coronary intervention: Impact on restoration of regional myocardial perfusion in reperfused myocardium during the subacute phase of myocardial infarction

BackgroundThe impact of nicorandil as adjunctive therapy for percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI) is controversial. We performed 15O-labeled water positron emission tomography (PET) to quantify regional myocardial perfusion in patients with STEMI who received nicorandil or no adjunctive therapy during PCI. MethodsPCI was performed within 8h after STEMI onset in 33 patients. 14 patients received intracoronary nicorandil 2mg immediately after recanalization of the culprit lesion (Nico group). After 3–4weeks, PET was performed in which myocardial blood flow (MBF) was measured at baseline and during adenosine triphosphate (ATP)-induced hyperemia. Myocardial vascular resistance (MVR) was calculated for all segments. Data were obtained from the reperfused (Rep) and normal segments (Cont) in each patient. ResultsIn patients not given nicorandil (No-Nico group), the MBF was significantly lower in Rep than that in Cont at baseline and during hyperemia (Cont vs. Rep: 0.82±0.14 vs. 0.68±0.11, P=0.001, ATP-Cont vs. ATP-Rep: 2.00±0.72 vs. 1.52±0.61, P=0.017), which was restored in the Nico group (Cont vs. Rep: 0.79±0.17 vs. 0.78±0.20; ATP-Cont vs. ATP-Rep: 2.02±0.84 vs. 1.84±0.62). MVR was elevated in Rep at baseline and during hyperemia in the No-Nico group. MVR elevation in Rep was prevented in the Nico group. Conclusions15O-labeled water PET was feasible for segmental analysis of MBF during the subacute phase of STEMI. It revealed that intracoronary administration of nicorandil to STEMI patients who underwent PCI prevented MVR elevation and thus restored MBF in the reperfused segments to a level similar to that in the normal segments.

Comparison of Myocardial Perfusion Evaluation with Single Versus Dual-Energy CT and Effect of Beam-Hardening Artifacts

We sought to explore the feasibility and diagnostic performance of dual-energy computed tomography (DECT) versus single-energy computed tomography (SECT) for the evaluation of myocardial perfusion in patients with intermediate to high likelihood of coronary artery disease. The present prospective study involved patients with known or suspected coronary artery disease referred for myocardial perfusion imaging by single-photon emission computed tomography. Forty patients were included in the study protocol and scanned using DECT imaging (n = 20) or SECT imaging (n = 20). The same pharmacologic stress was used for DECT, SECT, and single-photon emission computed tomography scans. A total of 1360 left ventricular segments were evaluated by DECT and SECT. The contrast-to-noise ratio was similar between groups (DECT 8.8 ± 2.9 vs. SECT 7.7 ± 4.2; P = .22). The diagnostic performance of DECT was greater than that of SECT in identifying perfusion defects (area under the receiver operating characteristic curve of DECT 0.90 [0.86-0.94] vs SECT 0.80 [0.76-0.84]; P = .0004) and remained unaffected when including only segments affected by beam-hardening artifacts (area under the receiver operating characteristic curve = DECT 0.90 [0.84-0.96) vs. SECT 0.77 [0.69-0.84]; P = .007). Our results suggest that myocardial perfusion by DECT imaging is feasible and might have improved diagnostic performance compared to SECT imaging for the assessment of myocardial CT perfusion. Furthermore, the diagnostic performance of DECT remained unaffected by the presence of beam-hardening artifacts.

Impact of P2Y12-mediated platelet reactivity on myocardial perfusion of patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: a cardiac magnetic resonance study

Background Whether high platelet reactivity (HPR) at the time of angiography is associated with worse myocardial reperfusion after primary percutaneous coronary intervention (PPCI) for ST-segment elevation myocardial infarction (STEMI) is unknown. This study aimed to assess the impact of HPR on infarct size and reperfusion injury determined by cardiac magnetic resonance (CMR) in patients with STEMI undergoing PPCI. Methods Patients with STEMI undergoing PPCI and pretreated with a P2Y12-receptor antagonist (clopidogrel, prasugrel or ticagrelor) underwent platelet function testing at the time of angiography and a CMR from 7 to 10 days after the index event. Platelet function testing was performed with the VerifyNow assay. HPR was defined according to expert consensus definitions. Central core laboratorymasked analyses for quantified ventricular function,

Incremental value of myocardial perfusion over coronary angiography by spectral computed tomography in patients with intermediate to high likelihood of coronary artery disease

PurposeWe sought to explore the diagnostic performance of dual energy computed tomography (DECT) for the evaluation of myocardial perfusion in patients with intermediate to high likelihood of coronary artery disease (CAD). Materials and methodsConsecutive patients with known or suspected CAD referred for myocardial perfusion imaging by single-photon emission computed tomography (SPECT) constituted the study population and were scanned using a DECT scanner equipped with gemstone detectors for spectral imaging, and a SPECT. The same pharmacological stress was used for both scans. ResultsTwenty-five patients were prospectively included in the study protocol. The mean age was 63.4±10.6 years. The total mean effective radiation dose was 7.5±1.2mSv with DECT and 8.2±1.7mSv with SPECT (p=0.007). A total of 425 left ventricular segments were evaluated by DECT, showing a reliable accuracy for the detection of reversible perfusion defects [area under ROC curve (AUC) 0.84 (0.80–0.87)]. Furthermore, adding stress myocardial perfusion provided a significant incremental value over anatomical evaluation alone by computed tomography coronary angiography [AUC 0.70 (0.65–0.74), p=0.003]. ConclusionsIn this pilot investigation, stress myocardial perfusion by DECT demonstrated a significant incremental value over anatomical evaluation alone by CTCA for the detection of reversible perfusion defects.

Intracoronary Transplantation of CD34+ Cells Is Associated With Improved Myocardial Perfusion in Patients With Nonischemic Dilated Cardiomyopathy

BackgroundWe investigated the effects of intracoronary transplantation of CD34+ cells on myocardial perfusion in patients with nonischemic dilated cardiomyopathy (DCM). Methods and ResultsWe enrolled 21 patients with DCM (left ventricular ejection fraction [LVEF] <40%, New York Heart Association functional class III) who underwent peripheral stem cell mobilization with granulocyte-colony stimulating factor (G-CSF). CD34+ cells were collected by means of apheresis. Patients underwent myocardial perfusion imaging, and CD34+ cells were injected in the coronary artery supplying viable segments with reduced myocardial perfusion and regional dysfunction. Myocardial perfusion imaging was repeated 6 months later. Clinical response to stem cell therapy was predefined as a change in LVEF >5%. The majority of patients were men (81%) with an overall mean age 53 ± 9 years, LVEF 25 ± 5%, and 6-minute walking distance 354 ± 71 m. Myocardial perfusion defects at rest were observed in 86% of patients and were more common in the left anterior descending territory (50%). At 6 months' follow-up, there was a significant improvement in rest myocardial perfusion scores (6.3 ± 5.8 vs 3.1 ± 4.3; P < .001), LVEF (25 ± 7% vs 29 ± 8%; P = .005), and 6-minute walking distance (354 ± 71 m vs 404 ± 91 m; P < .001). Responders to stem cell therapy had lower summed rest perfusion score at both baseline (3.2 ± 3.0 vs 9.1 ± 6.3; P = .015) and follow-up (1.0 ± 1.5 vs 5.0 ± 5.1; P = .028). ConclusionsCD34+ cell transplantation may lead to improved myocardial perfusion in patients with nonischemic DCM. Patients with less severe myocardial perfusion defects at baseline may have an increased likelihood to respond to intracoronary CD34+ cell transplantation.

Angiographic characteristics of definite stent thrombosis: role of thrombus grade, collaterals, epicardial coronary flow, and myocardial perfusion.

To characterize the prevalence of thrombus burden, collateral vessels to the infarct-related artery, epicardial coronary artery flow, and myocardial perfusion in patients with angiographically confirmed definite stent thrombosis (ST), and to define their relationship with associated treatments and outcomes. Angiographic characteristics of ST are not well defined. All cases of angiographically determined ST at five academic hospitals from 2005 to 2012 were reviewed. Demographic, procedural, and angiographic characteristics were recorded. In-hospital and 1-year follow-up data were obtained. Among 205 cases of angiographic definite ST (60 ± 8 years; 87% male), the majority presented with late/very late ST (69%) and STEMI (66%). High-risk angiographic findings at presentation included thrombus grade 4-5 (87%), absence of collateral vessels (76%), and reduced initial TIMI 3 flow (90%). Final TIMI 3 flow was achieved in 90% of patients and was associated with greater use of aspiration thrombectomy (60% vs. 25%; P = 0.003), glycoprotein IIb/IIIa inhibitors (80% vs. 30%, P < 0.001), and repeat stenting (67% vs. 10%, P < 0.001). A final myocardial perfusion grade of 2-3 was achieved in 79% of patients and was associated with greater use of aspiration thrombectomy (61% vs. 36%, P = 0.003). After multivariable logistic regression, aspiration thrombectomy (AOR 2.6, 95% CI 1.3-5.2) and implantation of a new stent (AOR 2.1, 95% CI 1.1-4.3) were associated with optimal combined epicardial flow and myocardial perfusion. At 1-year follow-up, significantly lower risk of repeat ST (HR 0.1; 95% CI 0.1,0.2; P < 0.001) among patients with initial TIMI 3 flow at index ST was observed. The majority of ST patients present with late/very late ST with high thrombus burden and STEMI. Presence of collateral vessels and low thrombus burden is cardioprotective, while reduced initial TIMI flow is associated with larger infarct size and recurrent ST. Aspiration thrombectomy and repeat stenting are associated with improved epicardial coronary artery flow and myocardial perfusion among patients treated for ST. © 2014 Wiley Periodicals, Inc.

Comparison of Myocardial Perfusion during Hemodialysis and Hemodiafiltration

Background: We compared myocardial perfusion in patients first on conventional hemodialysis (HD) and then on hemodiafiltration (HDF). Methods: Myocardial perfusion scintigraphy was performed in 25 patients pre- and post-HD. Patients were then converted to HDF for 3 months prior to repeating the scintigraphy. ^99mTc-methoxyisobutylisonitrile was administered intravenously pre-dialysis and then within the last hour of dialysis. Up to 90 min after injection, tomographic images were obtained. Clinical and laboratory data were collected pre- and post-dialysis. Results: Five patients did not complete the study. Patients entering the study were on average 41.7 years old and on HD for 4 years (median). The mean standard Kt/V for the two procedures was not statistically different (1.55 for HD and 1.48 for HDF). The mean substitution volume for HDF was 18.48 liters. There were no significant differences in changes in blood pressures between HD and HDF (p = 0.22). There were no significant differences in myocardial perfusion defects in patients on HD compared with those on HDF. During dialysis in both studies, the data showed a general trend to worsening of perfusion defects. Conclusions: There was no advantage of HDF over HD with no statistical difference in perfusion defects between HD and HDF. There was a trend to worsening of perfusion defects during dialysis in the majority on HD and HDF. Midweek dialysis perfusion scores appeared to be consistently lower than early-week dialysis, but this was not statistically significant. The pathogenesis of the defects may lie at a microcirculatory level.

Noninvasive Evaluation of Coronary Collateral Arterial Flow by Coronary Computed Tomographic Angiography

Coronary collateral flow is an alternative source of myocardial perfusion in patients with totally occluded coronary arteries. Clinical evaluation of collateral flow has been limited by the need of invasive measurements. We investigated whether noninvasive coronary computed tomographic angiography can evaluate the angiographic extent of coronary collateral flow. We enrolled 325 coronary computed tomographic angiography cases with angiographically confirmed chronic total occlusion (median age, 63 years; men 83%). Transluminal attenuation gradient (TAG), which reflects the kinetics of contrast media in coronary artery, of an entire artery as well as of a distal vessel was assessed to evaluate the flow in entire vessel and distal vessel. TAGs were validated against visually assessed angiographic collateral connection and Rentrop grading. TAG of an entire artery increased consistently according to the angiographic extent of collateral flow (P<0.001). Well-developed collaterals, defined by highest collateral connection and Rentrop grades (n=103), could be predicted by TAG of an entire artery (cutoff, ≥-7.6 Hounsfield units/10 mm; c-statistics, 0.72; sensitivity, 65%; specificity, 73%; positive predictive value, 52%; negative predictive value, 82%). TAG of a distal vessel could discriminate the antegrade (n=143) and retrograde (n=182) flows in distal artery (cutoff, 0.0 Hounsfield unit/10 mm; c-statistics, 0.88; sensitivity, 78%; specificity, 85%; positive predictive value, 87%; negative predictive value, 75%). TAG, an intracoronary attenuation-based analysis of coronary computed tomographic angiography, moderately reflected the functional extent and direction of collateral flow.

CRT-137 Myocardial Perfusion in Patients with Total Occlusion of a Single Coronary Artery with and without Collateral Circulation

Previous studies that investigated the effects of coronary collateral circulation on myocardial perfusion were compromised by inclusion of patients with multivessel coronary artery disease, incomplete occlusion, prior myocardial infarction, or a combination of these. In this study we will

Efficacy of Combination Treatment with Intracoronary Abciximab and Aspiration Thrombectomy on Myocardial Perfusion in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Coronary Stenting

PurposeWe aimed to investigate whether combination therapy using intracoronary (IC) abciximab and aspiration thrombectomy (AT) enhances myocardial perfusion compared to each treatment alone in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).Materials and MethodsWe enrolled 40 patients with STEMI, who presented within 6 h of symptom onset and had Thrombolysis in MI flow 0/1 or a large angiographic thrombus burden (grade 3/4). Patients were randomly divided into 3 groups: 10 patients who received a bolus of IC abciximab (0.25 mg/kg); 10 patients who received only AT; and 20 patients who received both treatments. The index of microcirculatory resistance (IMR) was measured with a pressure sensor/thermistor-tipped guidewire following successful PCI. Microvascular obstruction (MVO) was assessed using cardiac magnetic resonance imaging on day 5.ResultsIMR was lower in the combination group than in the IC abciximab group (23.5±7.4 U vs. 66.9±48.7 U, p=0.001) and tended to be lower than in the AT group, with barely missed significance (23.5±7.4 U vs. 37.2±26.1 U, p=0.07). MVO was observed less frequently in the combination group than in the IC abciximab group (18.8% vs. 88.9%, p=0.002) and tended to occur less frequently than in the AT group (18.8% vs. 66.7%, p=0.054). No difference of IMR and MVO was found between the IC abciximab and the AT group (66.9±48.7 U vs. 37.2±26.1 U, p=0.451 for IMR; 88.9% vs. 66.7%, p=0.525 for MVO, respectively).ConclusionCombination treatment using IC abciximab and AT may synergistically improve myocardial perfusion in patients with STEMI undergoing primary PCI (Trial Registration: clinicaltrials. gov Identifier: NCT01404507).

Coronary plaque imaging by coronary computed tomography angiography

Coronary computed tomography angiography (CTA) has become the useful noninvasive imaging modality alternative to the invasive coronary angiography for detecting coronary artery stenoses in patients with suspected coronary artery disease (CAD). With the development of technical aspects of coronary CTA, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology and patients outcomes by coronary CTA. In this review we discuss the coronary plaque morphology estimated by CTA beyond coronary angiography including the comparison to the currently available other imaging modalities used to examine morphological characteristics of the atherosclerotic plaque. Furthermore, this review underlies the value of a combined assessment of coronary anatomy and myocardial perfusion in patients with CAD, and adds to an increasing body of evidence suggesting an added diagnostic value when combining both modalities. We hope that an integrated, multi-modality imaging approach will become the gold standard for noninvasive evaluation of coronary plaque morphology and outcome data in clinical practice.

Effect of clinical and RBC hemorheological parameters on myocardial perfusion in patients with type 2 diabetes mellitus.

Myocardial ischemia may be present even when there is no significant stenosis of the epicardial coronary artery, or after coronary angioplasty for significant coronary artery disease. This phenomenon is related to disturbance of the coronary microcirculation or vasomotor tone. The aim of this study was to determine the influence of clinical and RBC hemorheological factors, such as RBC deformability and aggregation, on myocardial perfusion in patients with type 2 diabetes mellitus (DM) when compared to patients without DM, presenting with stable angina or acute coronary syndrome. Myocardial perfusion was graded using the myocardial blush grade (MBG) which describes the relative "blush" or intensity of the radio-opacity of myocardial tissue observed after an epicardial coronary injection of contrast medium during coronary angiography. MBG was counted before any medical or mechanical intervention, and in the myocardial territory without anatomical flow limitation (<50% of luminal narrowing on coronary angiogram), in order to remove the direct influence of anatomical stenosis. Myocardial perfusion in this region was associated with diabetes, renal function, LV diastolic function, inflammatory biomarkers such as hs-CRP, fibrinogen and ESR, but not with the clinical presentation. Among the hemorheological parameters, reduced myocardial perfusion was linked to increased RBC aggregation, but not to variation in RBC deformability. In conclusion, myocardial perfusion was affected by diabetes, left ventricular diastolic function, and inflammatory activity indicated by clinical parameters, and by the hemorheological factor RBC aggregation.

Prevalence and pattern of abnormal myocardial perfusion in patients with isolated coronary artery ectasia: study by 99mTc-sestamibi radionuclide scintigraphy

We explored the prevalence and pattern of abnormal myocardial perfusion in patients with isolated coronary artery ectasia (CAE), as demonstrated by (99m)Tc-sestamibi scintigraphy. Prospectively, we enrolled 35 patients with angiographically documented CAE and no significant coronary obstruction, who underwent elective coronary angiography. Patients underwent Stress-rest (99m)Tc-sestamibi scintigraphy within 4 days of coronary angiography. They were divided into 2 groups: group I: with normal perfusion scan; and group II: with reversible perfusion defects. The mean age was 49.6 ± 6.9 years; 34 (97.1 %) were males. Seventy-nine (75.2 %) arteries were affected by CAE. Among 79 arteries affected by CAE, affection was diffuse in 37 (46.8 %). Thirteen (37.1 %) patients had normal perfusion scan (group I), whereas 22 (62.9 %) had reversible perfusion defects (group II). Among 22 patients with reversible perfusion defects, 20 (90.9 %) had mild and 2 (9.1 %) had moderate ischemia. Among 49 myocardial segments with reversible perfusion defects, 22 (44.9 %) were basal, 18 (36.7 %) mid-, and 9 (18.4 %) apical segments. Diffuse CAE was significantly more prevalent in group II versus group I, in all 3 major coronary arteries (p < 0.05 for all). In patients with isolated CAE who underwent elective coronary angiography, reversible perfusion defects demonstrated by (99m)Tc-sestamibi scintigraphy were rather prevalent, mostly mild, more likely to affect the basal and mid-segments of the myocardium, and more frequently associated with diffuse ectasia.

Association between neutrophil–lymphocyte ratio and impaired myocardial perfusion in patients with known or suspected coronary disease

ObjectiveTo determine whether an elevated neutrophil–lymphocyte ratio (NLR) is associated with chronically impaired myocardial perfusion in patients with known or suspected coronary disease. BackgroundElevated NLRs are positively associated with cardiac events, anatomic coronary disease, and myocardial infarct size. However, no study has evaluated the association between NLR and chronically impaired myocardial perfusion. MethodsThis study included 683 patients undergoing cardiac positron emission tomography (PET) with a calculable NLR within 90 days of PET. The primary outcome was myocardial perfusion defect size measured in percent of left ventricular mass (%LV60). ResultsNLR was independently associated with %LV60 when analyzed as both a continuous and binary outcome (p < 0.001). Individuals with NLR above the 90th percentile had a 5-fold increased likelihood of significant perfusion defects compared to individuals with NLR between the 10th and 25th percentiles (Odds ratio = 4.7, p < 0.001). ConclusionAn elevated NLR demonstrated strong associations with myocardial perfusion.