Elevated C-reactive protein levels and coronary microvascular dysfunction in patients with coronary artery disease

Performance of drug-coated balloons in coronary and below-the-knee arteries: Anatomical, physiological and pathological considerations

Below-the-knee (infrapopliteal) atherosclerotic disease, which presents as chronic limb-threatening ischemia (CLTI) in nearly 50% of patients, represents a treatment challenge when it comes to the endovascular intervention arm of management. Due to reduced tissue perfusion, patients usually experience pain at rest and atrophic changes correlated to the extent of the compromised perfusion. Unfortunately, the prognosis remains unsatisfactory with 30% of patients requiring major amputation and a mortality rate of 25% within 1 year. To date, randomized multicentre trials of endovascular intervention have shown that drug-eluting stents (DES) increase patency rate and lower target lesion revascularization rate compared to plain balloon angioplasty and bare-metal stents. The majority of these trials recruited patients with focal infrapopliteal lesions, while most patients requiring endovascular intervention have complex and diffuse atherosclerotic disease. Moreover, due to the nature of the infrapopliteal arteries, the use of long DES is limited. Following recent results of drug-coated balloons (DCBs) in the treatment of femoropopliteal and coronary arteries, it was hoped that similar effective results would be achieved in the infrapopliteal arteries. In reality, multicentre trials have failed to support the proposed hypothesis and no advantage was found in using DCBs in comparison to plain balloon angioplasty. This review aims to explore anatomical, physiological and pathological differences between lesions of the infrapopliteal and coronary arteries to explain the differences in outcome when using DCBs.

Impact of renal denervation on patients with coronary microvascular dysfunction: study rationale and design

AIMS

Long-standing hypertension may cause an impairment in microvascular coronary circulation, which is involved in many different cardiac conditions. Renal sympathetic denervation (RDN) has been successfully proven as a valuable therapeutic choice for patients with resistant hypertension; moreover, the procedure looks promising in other settings, such as heart failure and atrial fibrillation, given its ability to downregulate the sympathetic nervous system, which is a recognized driver in these conditions as well as in microvascular dysfunction progression. The aim of this study is to explore the effect of RDN on coronary physiology in patients with ascertained coronary microvascular dysfunction and resistant hypertension.

METHODS

This is a multicenter, prospective, nonrandomized, open-label, interventional study. Consecutive patients with resistant hypertension, nonobstructive coronary artery disease (NOCAD) and documented microvascular dysfunction will be enrolled. Patients will undergo RDN by Spyral Symplicity 3 (Medtronic Inc, Minneapolis, Minnesota, USA) and reassessment of coronary microvascular function 6 months after the procedure. Primary endpoint will be the difference in the index of microcirculatory resistance.

CONCLUSION

The IMPRESSION study seeks to evaluate if there is any pleiotropic effect of the RDN procedure that results in modulation of microvascular function; if observed, this would be the first evidence showing RDN as a valuable therapy to revert hypertension-related microvascular dysfunction.

Incremental effect of coronary obstruction on myocardial microvascular dysfunction in type 2 diabetes mellitus patients evaluated by first-pass perfusion CMR study

BACKGROUND

Type 2 diabetes mellitus (T2DM) frequently coexists with obstructive coronary artery disease (OCAD), which are at increased risk for cardiovascular morbidity and mortality. This study aimed to investigate the impact of coronary obstruction on myocardial microcirculation function in T2DM patients, and explore independent predictors of reduced coronary microvascular perfusion.

METHODS

Cardiac magnetic resonance (CMR) scanning was performed on 297 T2DM patients {188 patients without OCAD [T2DM(OCAD -)] and 109 with [T2DM(OCAD +)]} and 89 control subjects. CMR-derived perfusion parameters, including upslope, max signal intensity (MaxSI), and time to maximum signal intensity (TTM) in global and segmental (basal, mid-ventricular, and apical slices) were measured and compared among observed groups. According to the median of Gensini score (64), T2DM(OCAD +) patients were subdivided into two groups. Univariable and multivariable linear regression analyses were performed to identify independent predictors of microcirculation dysfunction.

RESULTS

T2DM(OCAD -) patients, when compared to control subjects, had reduced upslope and prolonged TTM in global and all of three slices (all P < 0.05). T2DM(OCAD +) patients showed a significantly more severe impairment of microvascular perfusion than T2DM(OCAD -) patients and control subjects with a more marked decline upslope and prolongation TTM in global and three slices (all P < 0.05). From control subjects, through T2DM(OCAD +) patients with Gensini score ≤ 64, to those patients with Gensini score > 64 group, the upslope declined and TTM prolonged progressively in global and mid-ventricular slice (all P < 0.05). The presence of OCAD was independently correlated with reduced global upslope (β =  - 0.104, P < 0.05) and global TTM (β = 0.105, P < 0.05) in patients with T2DM. Among T2DM(OCAD +) patients, Gensini score was associated with prolonged global TTM (r = 0.34, P < 0.001).

CONCLUSIONS

Coronary artery obstruction in the context of T2DM exacerbated myocardial microcirculation damage. The presence of OCAD and Gensini score were independent predictors of decreased microvascular function.

TRIAL REGISTRATION

Retrospectively registered.

Concurrently Low Coronary Flow Reserve and Low Index of Microvascular Resistance Are Associated With Elevated Resting Coronary Flow in Patients With Chest Pain and Nonobstructive Coronary Arteries

BACKGROUND

Coronary microvascular function can be distinctly quantified using the coronary flow reserve (CFR) and index of microvascular resistance (IMR). Patients with low CFR can present with low or high IMR, although the prevalence and clinical characteristics of these patient groups remain unclear.

METHODS

One hundred ninety-nine patients underwent coronary microvascular assessments using coronary thermodilution techniques. A pressure-temperature sensor-tipped guidewire measured proximal and distal coronary pressure, whereas the inverse of the mean transit time to room temperature saline was used to measure coronary blood flow. The CFR and IMR were quantified during adenosine and acetylcholine hyperemia.

RESULTS

Low adenosine and acetylcholine CFR was observed in 70 and 49 patients, respectively, whereas low CFR/low IMR to adenosine and acetylcholine was observed in 39(56%) and 19(39%) patients, respectively. Despite similar adenosine CFR, patients with low CFR/low IMR had increased resting (2.8±1.2 versus 1.3±0.4s^-1) and hyperemic coronary blood flow (4.8±1.5 versus 2.1±0.5s^-1) compared with patients with low CFR/high IMR (both P<0.01). The same pattern was observed in response to acetylcholine. Patients with low CFR/low IMR to adenosine were younger (56±12 versus 63±10 years), women (84% versus 66%), had fewer coronary risk factors (1.1±1.0 versus 1.6±1.1), lower hemoglobin A1c (5.8±0.7 versus 6.1±0.9 mmol/L), and thinner septal thickness (8.5±2.5 versus 9.9±1.6 mm) compared with patients with low CFR/high IMR to adenosine (all P<0.05).

CONCLUSIONS

Low CFR/low IMR to adenosine and acetylcholine are associated with elevated resting coronary blood flow and preserved hyperemic coronary blood flow. These patients present with distinct phenotypic characteristics. Simultaneous CFR and IMR measures appear necessary to differentiate these endotypes.

Inflammation in Metabolic Cardiomyopathy

Overlapping pandemics of lifestyle-related diseases pose a substantial threat to cardiovascular health. Apart from coronary artery disease, metabolic disturbances linked to obesity, insulin resistance and diabetes directly compromise myocardial structure and function through independent and shared mechanisms heavily involving inflammatory signals. Accumulating evidence indicates that metabolic dysregulation causes systemic inflammation, which in turn aggravates cardiovascular disease. Indeed, elevated systemic levels of pro-inflammatory cytokines and metabolic substrates induce an inflammatory state in different cardiac cells and lead to subcellular alterations thereby promoting maladaptive myocardial remodeling. At the cellular level, inflammation-induced oxidative stress, mitochondrial dysfunction, impaired calcium handling, and lipotoxicity contribute to cardiomyocyte hypertrophy and dysfunction, extracellular matrix accumulation and microvascular disease. In cardiometabolic patients, myocardial inflammation is maintained by innate immune cell activation mediated by pattern recognition receptors such as Toll-like receptor 4 (TLR4) and downstream activation of the NLRP3 inflammasome and NF-κB-dependent pathways. Chronic low-grade inflammation progressively alters metabolic processes in the heart, leading to a metabolic cardiomyopathy (MC) phenotype and eventually to heart failure with preserved ejection fraction (HFpEF). In accordance with preclinical data, observational studies consistently showed increased inflammatory markers and cardiometabolic features in patients with HFpEF. Future treatment approaches of MC may target inflammatory mediators as they are closely intertwined with cardiac nutrient metabolism. Here, we review current evidence on inflammatory processes involved in the development of MC and provide an overview of nutrient and cytokine-driven pro-inflammatory effects stratified by cell type.

Association of C-Reactive Protein to Albumin Ratio in Patients with Isolated Coronary Artery Ectasia

Fundamento

A ectasia da artéria coronária (EAC) é definida como a dilatação difusa ou localizada do lúmen da artéria coronária com diâmetro de 1,5 a 2,0 vezes o diâmetro da artéria coronária normal adjacente. A relação proteína C-reativa/albumina (CAR, sigla em inglês) é um marcador inflamatório útil que tem sido documentado em doença arterial coronariana.

Objetivo

Analisar a associação entre a EAC e a CAR.

Métodos

Um protocolo caso-controle foi utilizado neste estudo. Foram incluídos 102 pacientesconsecutivos com EAC isolada sem estenose (56 homens e 46 mulheres; idade média de 60,4 ± 8,8 anos). O grupo controle era constituido pelo mesmo número de pacientes pareados por sexo e idade com artérias coronárias normais (55 homens e 47 mulheres; idade média de 61,2 ± 9,1 anos). Características clínicas, achados laboratoriais e histórico de uso de medicamentos foram registrados. Foram realizados teste t de Student, teste U de Mann-Whitney, teste do qui-quadrado, análise de regressão linear e logística. Foi considerado estatisticamente significativo p bilateral < 0,05.

Resultados

A CAR estava aumentada nos pacientes com EAC em comparação com os controles (32 e 16; p < 0,001). Além disso, foi verificado que a CAR era um preditor independente da EAC (razão de chances = 2,202; intervalo de confiança 95%, 1,184 – 5,365; p < 0,001).

Conclusão

No presente estudo, determinamos que os níveis da CAR estavam significativamente mais altos no grupo EAC que no grupo controle e a CAR estava significativamente correlacionada com a EAC. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

Coronary Microvascular Dysfunction

Many patients with chest pain undergoing coronary angiography do not show significant obstructive coronary lesions. A substantial proportion of these patients have abnormalities in the function and structure of coronary microcirculation due to endothelial and smooth muscle cell dysfunction. The coronary microcirculation has a fundamental role in the regulation of coronary blood flow in response to cardiac oxygen requirements. Impairment of this mechanism, defined as coronary microvascular dysfunction (CMD), carries an increased risk of adverse cardiovascular clinical outcomes. Coronary endothelial dysfunction accounts for approximately two-thirds of clinical conditions presenting with symptoms and signs of myocardial ischemia without obstructive coronary disease, termed "ischemia with non-obstructive coronary artery disease" (INOCA) and for a small proportion of "myocardial infarction with non-obstructive coronary artery disease" (MINOCA). More frequently, the clinical presentation of INOCA is microvascular angina due to CMD, while some patients present vasospastic angina due to epicardial spasm, and mixed epicardial and microvascular forms. CMD may be associated with focal and diffuse epicardial coronary atherosclerosis, which may reinforce each other. Both INOCA and MINOCA are more common in females. Clinical classification of CMD includes the association with conditions in which atherosclerosis has limited relevance, with non-obstructive atherosclerosis, and with obstructive atherosclerosis. Several studies already exist which support the evidence that CMD is part of systemic microvascular disease involving multiple organs, such as brain and kidney. Moreover, CMD is strongly associated with the development of heart failure with preserved ejection fraction (HFpEF), diabetes, hypertensive heart disease, and also chronic inflammatory and autoimmune diseases. Since coronary microcirculation is not visible on invasive angiography or computed tomographic coronary angiography (CTCA), the diagnosis of CMD is usually based on functional assessment of microcirculation, which can be performed by both invasive and non-invasive methods, including the assessment of delayed flow of contrast during angiography, measurement of coronary flow reserve (CFR) and index of microvascular resistance (IMR), evaluation of angina induced by intracoronary acetylcholine infusion, and assessment of myocardial perfusion by positron emission tomography (PET) and magnetic resonance (CMR).

Prognostic value of C-reactive protein/albumin ratio in ST-segment elevation myocardial infarction

Serum C-reactive protein (CRP)/albumin ratio (CAR) is demonstrated as a more precise marker in determining the prognosis of critical diseases than albumin and CRP levels, separately. Recently, inflammatory biomarkers are increasingly used for both screening and prognosis of coronary artery disease (CAD). As an ischemia-dependent risk index, CAR is an independent marker of in-hospital and long-term all-cause mortality in ST-segment elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention. The results indicate that CAR is a more effective prognostic marker than either CRP or albumin.

Association Between C-Reactive Protein to Albumin Ratio and Left Ventricular Thrombus Formation Following Acute Anterior Myocardial Infarction

Left ventricular thrombus (LVT) is associated with inflammatory response in survivors with anterior ST-elevation myocardial infarction (STEMI). The C-reactive protein to albumin ratio (CAR) has been proposed as a marker of inflammation. However, there is a lack of data with respect to the role of CAR in LVT development. We investigated the relationship between CAR and LVT development in patients with anterior STEMI treated percutaneously; 955 consecutive patients were enrolled and LVT was observed in 126 (13.2%) patients. Clinical, demographic, and laboratory parameters were recorded. The CAR was significantly higher in patients with LVT (12.6 [8.6-16.1] vs 18.1 [11.5-23], P < .001). Other independent predictors for LVT development were lower ejection fraction, the presence of left ventricular apical aneurysm, proximal left anterior descending lesion location, glycoprotein IIb/IIIa inhibitors treatment, >1 diseased arteries, higher total protein level, neutrophil count, and peak creatine kinase myocardial band activity. In conclusion, the CAR may be useful as a simple tool for predicting LVT development among survivors of anterior STEMI.

Markers for Inflammation and Oxidative Stress in Patients with Coronary Artery Disease and Microvascular Disease – Is there a Difference?

Introduction: The clinical significance of inflammation (and markers such as resistin, hsCRP) and oxidative stress (e.g. 8-isoprostanes) for microvascular disease (MVD) and coronary artery disease (CAD) is still elusive.

Aims: To determine the role of the markers for inflammation and oxidative stress as independent markers for MVD.

Methods: Ninety consecutive patients were recruited: twenty-five of them had CAD; thirty – MVD and thirty-five were controls. The latter included patients with atypical chest pain, risk factors, lack of coronary artery disease and negative adenosine test. Coronary angiography was performed in all participants. The adenosine test was performed in those without CAD, hs CRP, resistin in plasma and urine 8-isoprostanes were measured. The correlation of all these indicators with CAD and MVD was analyzed.

Results: The 8-isoprostanes showed significant differences between patients with MVD and CAD (0,055/0,52 pg/mmol Cre; p = 0,028). The same trend was found between CAD patients and the control group (0,055/0,003 pg/mmol Cre; p = 0,041); as well as between those with MVD and the control group (0,52/0,003 pg/mmol Cre; p = 0,001). The highest values of 8-isoprostanes were detected in patients with MVD – 0,52 pg/mmol Cre. Markers for inflammation were similar in patients with MVD and CAD (hsCRP- p = 0,091; resistin − p = 0,32).

Conclusions: hs CRP, resistin and 8-isoprostanes are involved in the pathogenesis of both CAD and MVD. However, oxidative stress is probably more important for MVD, therefore 8-isoprostanes can be a part of panel of markers for its detection and analysis.

Relationship Between C-Reactive Protein to Albumin Ratio and Thrombus Burden in Patients With Acute Coronary Syndrome

Increased coronary thrombus burden is known to be a strong predictor of adverse cardiovascular (CV) outcomes. C-reactive protein to albumin ratio (CAR) can be used as a surrogate marker of pro-inflammation which is closely related to prothrombotic state. We aimed to evaluate the association between CAR and coronary thrombus burden in patients who presented with acute coronary syndrome (ACS). Patients who presented with ACS and treated with primary percutaneous coronary intervention were included in the study. Patients were divided into 2 groups as high thrombus burden and low thrombus burden. The study population included 347 patients with non-ST-segment elevation myocardial infarction (169 [48.7%]) and ST-segment elevation myocardial infarction (178 [51.3%]). The CAR was significantly higher in patients with higher thrombus burden (24.4 [1.2-30.2] vs 31.9 [2.2-31.3], P < .001). Independent predictors for increased thrombus burden were higher CRP level (odds ratio [OR]: 0.047; 95% confidence interval [CI]: 0.004-0.486; P = .010), lower serum albumin level (OR: 0.057; 95% CI: 0.033-0.990; P = .049), higher CAR (OR: 1.13; 95% CI: 1.03-1.23; P = .008), higher neutrophil–lymphocyte ratio (OR: 1.18; 95% CI: 1.05-1.31; P = .004), and baseline troponin I level (OR: 1.06; 95% CI: 1.01-1.13; P = .017). Novel CAR can be used as a reliable marker for increased coronary thrombus burden that is associated with adverse CV outcomes.

Usefulness of The C-Reactive Protein/Albumin Ratio for Predicting No-Reflow in ST-elevation myocardial infarction treated with primary percutaneous coronary intervention

BACKGROUND

The ratio of serum C-reactive protein (CRP) to albumin has been proven to be a more accurate indicator than albumin and CRP levels alone in determining the prognosis of patients with cancer and critical illness. The aim of this study was to determine whether the CRP/albumin ratio (CAR) can be linked to imperfect reperfusion that can worsen the prognosis of ST-elevation myocardial infarction (STEMI) in patients treated with primary percutaneous coronary intervention (pPCI).

MATERIALS AND METHODS

A total of 1217 consecutive STEMI patients who achieved epicardial vessel patency with pPCI were recruited to this study.

RESULTS

The study population was divided into 2 groups: reflow (n = 874) and no-reflow (NR) (n = 343) groups. The white blood cell count (WBC), neutrophil-to-lymphocyte ratio (NLR) and CAR (0.03 [0.01-0.04] vs 0.06 [0.03-0.12] (P < .001) were significantly higher in the NR group than in the reflow group, and these factors were found to be independent predictors of NR development. The best cut-off value of CAR predicting NR was 0.59 with a sensitivity of 54.7% and specificity of 86.7. The predictive power of CAR surpassed that of CRP, albumin, WBC count and NLR in the receiver operator curve (ROC) curve comparison.

CONCLUSION

No-reflow can be predicted by systemic inflammation markers including WBC count, NLR and CAR measured from the blood sample obtained on admission. CAR has a higher clinical value than CRP, albumin level, WBC count and NLR in NR prediction.

Evaluation of intermediate coronary stenoses in acute coronary syndromes using pressure guidewire

Fractional flow reserve (FFR) is increasingly used to guide myocardial revascularisation. However, supporting evidence regarding its use originates from studies that have enrolled mainly patients with stable angina, while patients with acute coronary syndromes (ACS) have not been included. Notably, multifactorial microvascular dysfunction and an increased sympathetic tone in patients with ACS may lead to blunted response to adenosine and false-negative results of FFR due to submaximal hyperaemia. This may raise the possibility of deferring treatment of stenosis that instead would have needed dilatation, thus leaving a residual risk of preventable cardiac events. In this literature review, we aim at summarising laboratory and clinical investigations concerning the use of FFR in culprit and non-culprit lesions in ACS. Furthermore, we will report recent data on instantaneous wave-free ratio, an adenosine-free index of functional stenosis severity, in stable coronary artery disease and in patients with ACS.

Diabetes is an independent predictor of right ventricular dysfunction post ST-elevation myocardial infarction

BACKGROUND

Diabetes mellitus (DM) is estimated to become the 7th leading cause of death by 2030. Right ventricular dysfunction (RVD) complicating ST elevation myocardial infarction (STEMI) is independently associated with a higher mortality; however the relationship between DM and RVD is currently unknown. The purpose of this study was to determine whether DM is an independent predictor for the presence of right ventricular dysfunction (RVD) post STEMI.

METHODS

106 patients post primary PCI for STEMI were enrolled in the study. Cardiac MRI was performed within 48-72 h after admission in order to assess ventricular function. Statistical analysis consisted initially of descriptive statistics including Chi square, Fisher's exact, or the Wilcoxon rank sum as appropriate. Subsequently, logistic regression analysis was performed to determine independent predictors of RVD.

RESULTS

The median age in the study was 58 years (IQR 53, 67). 30 % of the patients had diabetes. Of 99 patients for which RV data was available, 40 had RVD and 59 did not. Patients with DM were significantly more likely to have RVD when compared to those without diabetes (45 vs 22 %, p = 0.03). There was no significant difference in age, hypertension, smoking status, dyslipidemia, serum creatinine or peak CK levels between the two groups. After adjusting for other factors, presence of DM remained an independent predictor for the presence of RV dysfunction (OR 2.78, 95 % CI 1.12, 6.87, p = 0.03). Amongst diabetic patients, those with HbA1C ≥ 7 % had greater odds of having RVD vs those with HbA1C < 7 % (OR 5.58 (1.20, 25.78), p = 0.02).

CONCLUSIONS

The presence of DM conferred an approximately threefold greater odds of being associated with RVD post STEMI. No other major cardiovascular risk factors were independently associated with the presence of RVD.

Effect of inflammatory factor-induced cyclo-oxygenase expression on the development of reperfusion-related no-reflow phenomenon in acute myocardial infarction

No reflow after reperfusion therapy for myocardial infarction is a strong predictor of clinical outcome. Increased levels of inflammatory factors, including C-reactive protein (CRP), in patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI) may affect myocardial perfusion. However, why the no-reflow phenomenon increases in inflammation stress after PCI is not clear. The aim of the present study was to determine the effects and molecular mechanisms underlying the effects of CRP on the expression of cyclo-oxygenase (COX) on the development of the no-reflow phenomenon. There was a significant increase in plasma levels of CRP and interleukin (IL)-6 in no-reflow patients, suggesting that inflammatory factors play an important role in the development of the no-reflow phenomenon. The mechanisms involved were further evaluated after reperfusion in a rat model mimicking the no-reflow phenomenon. Compared with normal reflow rats, there were significant increases in both COX-1 and COX-2 in cardiac tissue from no-reflow rats. The COX inhibitor indomethacin (5 mg/kg, i.p.) significantly reduced the no-reflow area. In another series of experiments, human coronary artery endothelial cells (HCAEC) were treated with CRP at clinically relevant concentrations (5-25 μg/mL). C-Reactive protein significantly increased COX-1 and COX-2 levels in a time- and concentration-dependent manner. In addition, extracellular signal-regulated kinase (ERK) and Jun N-terminal kinase (JNK) were activated in CRP (5, 10, 25 μg/mL)-treated HCAEC cultures. Furthermore, the ERK inhibitor pd98059 (30 μmol/L) and the JNK inhibitor sp600125 (10 μmol/L) blocked CRP-induced COX-1 and COX-2 expression for 12 h. Together, the findings of the present study suggest that CRP can promote the development of the no-reflow phenomenon by increasing COX-1 and COX-2 expression, which is regulated, in part, via ERK and JNK activity.

Impact of accuracy of fractional flow reserve to reduction of microvascular resistance after intracoronary adenosine in patients with angina pectoris or non-ST-segment elevation myocardial infarction

Our study aimed to elucidate mechanisms underlying discordance between fractional flow reserve (FFR) and hyperemic stenosis resistance (hSR) in some patient subsets. To do this, we enrolled 30 consecutive patients with stable angina or non-ST elevation myocardial infarction (non-STEMI) and with a nonculprit intermediate coronary lesion (40% to 70%) by coronary angiography. We measured aortic pressure, flow velocity, and pressure distal to lesion simultaneously at basal level and during adenosine-induced (fixed intracoronary dose of 120 μg) hyperemia using a dual-sensor-equipped guidewire. Microvascular resistance (MR; pressure distal to lesion/flow velocity, mm Hg/cm/s) and variation (Δ) in MR levels were calculated both at baseline and after hyperemia, whereas FFR (cutoff <0.80) and hSR [(aortic pressure - pressure distal to lesion)/flow velocity, cutoff >0.80 mm Hg/cm/s] were assessed after intracoronary adenosine. Twenty-three patients (76.7%) showed concordance and 7 patients (23.3%) showed discordance between FFR and hSR (all cases with FFR >0.80 and hSR >0.80). Discordant patients presented more frequently with non-STEMI (85.7% vs 39.1%, p = 0.04), significantly higher C-reactive protein serum levels (median [interquartile range] 5.9 [5.1 to 6.8] vs 4.9 [3.7 to 6.2] mg/L, p = 0.007), and lower ΔMR (p = 0.03) values compared with concordant patients. In conclusion, patients with non-STEMI and those with increased C-reactive protein levels show a lower reduction in MR after intracoronary adenosine-induced hyperemia, leading to FFR underestimation.

Endothelial Dysfunction in Patients With Coronary Artery Disease

Background:

The use of flow-mediated dilation (FMD) as a surrogate indicator for the extent of coronary artery disease (CAD) remains largely unknown. We assessed FMD at the brachial artery in 89 consecutive patients undergoing coronary angiography.

Methods and Results:

Patients were classified in groups 0 to 3 according to the number of diseased vessels and the SYNTAX score was calculated. The FMD decreased significantly from groups 0 to 3 ( P < .001). There was a significant linear relation between SYNTAX score and FMD (corrected r2 = .64, P < .001). In multivariate analysis, a reduced FMD was the only significant independent predictor of the presence of CAD (odds ratio [OR] 1.78, P = .032) and of CAD severity (OR 1.85, P = .005).

Conclusion:

This study confirms that FMD is reduced in patients with CAD and that such reduction in FMD is related to the extent of the disease. Therefore, FMD at the brachial artery is likely to represent a reliable indicator of CAD burden.

Association of baseline C-reactive protein levels with periprocedural myocardial injury in patients undergoing percutaneous bifurcation intervention: a CACTUS study subanalysis

OBJECTIVES

To assess the predictive value of C-reactive protein (CRP) on periprocedural myocardial injury (PMI), evaluated by creatine kinase-myocardial band isoform (CK-MB) elevation in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation for the treatment of coronary bifurcation lesions is actually unknown.

BACKGROUND

Systemic inflammation as assessed by CRP has been associated with averse events after DES implantation. After PCI, the occurrence of PMI is common and has also been associated with worse outcomes. Finally, bifurcations are frequently encountered anatomically complex lesions which the treatment is associated with higher complication rate compared with simple lesions.

METHODS

A total of 96 patients (66 ± 10 years, 70 men) from the Coronary bifurcations: Application of the Crushing Technique Using Sirolimus-eluting stents (CACTUS) trial who had baseline CRP dosage and both baseline and postprocedural CK-MB measurement were included.

RESULTS

A complex bifurcation strategy was implemented in 53 (55%) patients, and angiographic success was achieved in all but two (2%) patients. Periprocedural myocardial necrosis (increase of CK-MB between one and three times the upper limit of normal [ULN]) was observed in 12 (13%) patients, and four (4%) patients had PCI-related myocardial infarction (increase of CK-MB more than three times ULN). Notably, progressively higher CRP levels were observed in patients with different increase in CK-MB (P = 0.041). Moreover, CRP >1 mg/L significantly predicted CK-MB rise (odds ratio 5.6, 95% confidence interval 1.5-4.3, P = 0.011).

CONCLUSION

In the setting of true coronary bifurcations treated by DES, baseline CRP levels were significantly associated with both the incidence and the extent of PMI.

Role of C-reactive protein in determining microvascular function in patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention

The extent of coronary microvascular dysfunction might be related, not only to patient characteristics and procedural factors, but also to the inflammatory status. The aim of the present study was to examine a possible association between inflammation, as reflected by the serum C-reactive protein (CRP) levels, and the extent of baseline and post-percutaneous coronary intervention (PCI) coronary microvascular dysfunction in patients with non-ST-segment elevation acute coronary syndrome undergoing PCI. A total of 42 patients undergoing PCI for non-ST-segment elevation acute coronary syndrome were enrolled. Coronary microvascular resistance (MR) was determined in the territory of culprit artery using a Doppler probe- and a pressure sensor-equipped guidewire both before (taking the collateral blood into account) and after PCI. The periprocedural changes in MR were calculated. The CRP levels at admission were correlated with the pre-PCI MR (r = 0.498, p = 0.001), post-PCI MR (r = 0.429, p = 0.005), and periprocedural changes in MR (r = 0.785, p <0.001). On multivariate regression analysis, the only predictor of the pre-PCI (β = 0.531, p = 0.002) and post-PCI (β = 0.471, p = 0.012) MR was the serum CRP concentration. Likewise, the periprocedural changes in MR was predicted by the serum CRP levels (β = 0.677, p = 0.001) and the presence of angiographic thrombus (β = -0.275, p = 0.02). In conclusion, these results have shown that the CRP level is related to increased coronary MR in the territory of the culprit lesion. This suggests that inflammatory processes might play a role in microvascular impairment in patients with non-ST-segment elevation acute coronary syndrome.

Quantitative magnetic resonance imaging can distinguish remodeling mechanisms after acute myocardial infarction based on the severity of ischemic insult

The type and extent of myocardial infarction encountered clinically is primarily determined by the severity of the initial ischemic insult. The purpose of the study was to differentiate longitudinal fluctuations in remodeling mechanisms in porcine myocardium following different ischemic insult durations. Animals (N = 8) were subjected to coronary balloon occlusion for either 90 or 45 min, followed by reperfusion. Imaging was performed on a 3 T MRI scanner between day-2 and week-6 postinfarction with edema quantified by T2, hemorrhage by T2*, vasodilatory function by blood-oxygenation-level-dependent T2 alterations and infarction/microvascular obstruction by contrast-enhanced imaging. The 90-min model produced large transmural infarcts with hemorrhage and microvascular obstruction, while the 45 min produced small nontransmural and nonhemorrhagic infarction. In the 90-min group, elevation of end-diastolic-volume, reduced cardiac function, persistence of edema, and prolonged vasodilatory dysfunction were all indicative of adverse remodeling; in contrast, the 45-min group showed no signs of adverse remodeling. The 45- and 90-min porcine models seem to be ideal for representing the low- and high-risk patient groups, respectively, commonly encountered in the clinic. Such in vivo characterization will be a key in predicting functional recovery and may potentially allow evaluation of novel therapies targeted to alleviate ischemic injury and prevent microvascular obstruction/hemorrhage.

Flow-dependent endothelial function and kidney dysfunction

The vascular endothelium constantly integrates biomechanical and humoral signals and responds by secreting or metabolizing multiple factors that act in an autocrine or paracrine manner on the vasculature and adjacent tissues. Several studies have documented the effects of blood flow on renal endothelial cells and its effects on the pathophysiology of the kidney. In contrast, less is known about the effects of acute flow cessation on renal endothelium and kidney function. Here we review our current knowledge on flow cessation, endothelial function, and kidney dysfunction in the context of two clinically relevant settings, namely, the no-reflow phenomenon, observed during periods of renal warm ischemia, and the cold storage of kidney transplants.

Microvascular dysfunction in the spectrum of coronary instability

The term "coronary instability" commonly refers to the sequence of events that lead from plaque erosion or rupture to the occurrence of acute coronary syndromes (ACS). However, evidence indicates that coronary microvascular dysfunction plays a relevant pathophysiologic and prognostic role in the setting of ACS, both in ST-segment elevation myocardial infarction and in non-ST-segment elevation ACS. Our group have recently demonstrated that Tako-Tsubo syndrome, which clinically mimics ACS, is sustained by a common pathophysiologic mechanism represented by reversible coronary microvascular dysfunction. Given this evidence, we propose a reappraisal of the concept of coronary instability, extending this notion from the dramatic event represented by plaque erosion or rupture to a more diffuse process that can acutely affect each segment of the coronary circulation.

Glycoprotein IIb-IIIa inhibitors

Platelets play a pivotal role in the pathogenesis of coronary artery disease and myocardial infarction. Therefore, great interests have been focused in the last decades on improvement in antiplatelet therapies, that currently are regarded as main pillars in the prevention and treatment of coronary artery disease, with special attention to glycoprotein IIb-IIIa (GP IIb-IIIa) receptors, that mediates the final stage of platelet activation. GP IIb-IIIa inhibitors, especially abciximab, have been shown to improve clinical outcome in patients undergoing primary angioplasty for STEMI. Upstream administration cannot routinely recommended, but may potentially be considered among high-risk patients within the first 4 h from symptoms onset. In case of periprocedural administration of antithrombotic therapy, Bivalirudin should be considered, especially in patients at high risk for bleeding complications. Among high-risk patients with acute coronary syndromes, an early invasive strategy with selective downstream administration of GP IIb-IIIa inhibitors is the strategy of choice, whereas bivalirudin should be considered in patients at high risk for bleeding complications. Among patients with unstable angina GP IIb-IIIa inhibitors should be considered only in case of evidence of intracoronary thrombus or in case of thrombotic complications (as provisional use). Further, randomized trials are certainly needed in the era of new oral antiplatelet therapies, and with strategies to prevent bleeding complications such as larger use of radial approach, mechanical closure devices, bivalirudin, or postprocedural protamine administration to promote early sheat removal.

Microvascular coronary dysfunction in women: pathophysiology, diagnosis, and management

Women exhibit a greater symptom burden, more functional disability, and a higher prevalence of no obstructive coronary artery disease compared to men when evaluated for signs and symptoms of myocardial ischemia. Microvascular coronary dysfunction (MCD), defined as limited coronary flow reserve and/or coronary endothelial dysfunction, is the predominant etiologic mechanism of ischemia in women with the triad of persistent chest pain, no obstructive coronary artery disease, and ischemia evidenced by stress testing. Evidence shows that approximately 50% of these patients have physiological evidence of MCD. MCD is associated with a 2.5% annual major adverse event rate that includes death, nonfatal myocardial infarction, nonfatal stroke, and congestive heart failure. Although tests such as adenosine stress cardiac magnetic resonance imaging may be a useful noninvasive method to predict subendocardial ischemia, the gold standard test to diagnose MCD is an invasive coronary reactivity testing. Early identification of MCD by coronary reactivity testing may be beneficial in prognostication and stratifying these patients for optimal medical therapy. Currently, understanding of MCD pathophysiology can be used to guide diagnosis and therapy. Continued research in MCD is needed to further advance our understanding.

Gender and microvascular angina

There are gender differences in the presentation, diagnosis, and treatment of chest pain. When compared to men, women may have more atypical presentations of chest pain. In addition, current diagnostic tools are often not definitive regarding cardiac etiology for chest pain in women. The current diagnostic model of chest pain focuses on significant obstructions within the large coronary arteries as the cause for angina. Microvascular angina (MVA) represents an under-recognized pathophysiologic mechanism that may explain the apparent disparities and elucidate an etiology for the common finding in women of chest pain, ischemia on stress testing, and no obstructive coronary artery disease (CAD) on angiography in the presence of abnormal coronary reactivity testing. Endothelial dysfunction, estrogen deficiency, and abnormal nociception play a role in the pathophysiology of MVA. Treatments are targeted toward these underlying mechanisms. Recognizing the role gender and other pathophysiologic models of chest pain can play in the work-up and treatment of angina may identify a treatable cardiac condition, that would otherwise be discounted as non-cardiac in origin.

Predicting the no-reflow phenomenon following successful percutaneous coronary intervention

In the setting of acute myocardial infarction, early and adequate reopening of an infarct-related artery is not necessarily followed by a complete restoration of myocardial perfusion. This condition is usually defined as ‘no-reflow’. The pathophysiology of no-reflow is multifactorial since extravascular compression, microvascular vasoconstriction, embolization during percutaneous coronary intervention, and platelet and neutrophil aggregates are involved. In the clinical arena, angiographic findings and easily available clinical parameters can predict the risk of no-reflow. More recently, several studies have demonstrated that biomarkers, especially those related to the pathogenetic components of no-reflow, could also have a prognostic role in the prediction and in the full understanding of the multiple mechanisms of this phenomenon. Thus, in this article, we investigate the role of several biomarkers on admission in predicting the occurrence of no-reflow following successful percutaneous coronary intervention.

Relation of elevated levels of plasma myeloperoxidase to impaired myocardial microcirculation after reperfusion in patients with acute myocardial infarction

Previous studies have shown that oxidative stress and endothelial dysfunction are related to impaired myocardial microcirculation after reperfusion. Moreover, elevated myeloperoxidase (MPO) levels are associated with endothelial dysfunction. Plasma MPO levels were measured in patients with ST-segment elevation acute myocardial infarction (n = 160) who had undergone percutaneous coronary stenting within 12 hours of symptom onset. We investigated whether the plasma MPO level at admission was associated with impaired myocardial microcirculation, as indicated by ST-segment resolution and myocardial blush grade after reperfusion, and left ventricular ejection fraction and remodeling at 6 months. The patients were divided into 2 groups according to the median MPO value for the entire cohort (low-MPO group < or =50 ng/ml, n = 80; high-MPO group >50 ng/ml, n = 80). ST-segment resolution and the myocardial blush grade were significantly lower in the high-MPO than in the low-MPO group (48 +/- 27% vs 61 +/- 24%, p <0.005; and 2.1 +/- 0.8 vs 2.4 +/- 0.7, p <0.01; respectively). Moreover, the percentage of increase in the left ventricular end-diastolic volume index was significantly greater and the left ventricular ejection fraction at 6 months was significantly lower in the high-MPO group than in the low-MPO group (8.2 +/- 24.7% vs -1.9 +/- 23.5%, p <0.05; and 46 +/- 9% vs 54 +/- 9%, p <0.0001, respectively). Multiple regression analysis showed that the plasma MPO level was an independent predictor of incomplete ST-segment resolution (odds ratio 6.94, 95% confidence interval 2.10 to 22.9, p = 0.0015). In conclusion, elevated plasma MPO levels at admission were associated with impaired myocardial microcirculation after reperfusion in patients with acute myocardial infarction.

C-reactive protein impairs coronary arteriolar dilation to prostacyclin synthase activation: role of peroxynitrite

Endothelium-derived vasodilators, i.e., nitric oxide (NO), prostacyclin (PGI(2)) and prostaglandin E(2) (PGE(2)), play important roles in maintaining cardiovascular homeostasis. C-reactive protein (CRP), a biomarker of inflammation and cardiovascular disease, has been shown to inhibit NO-mediated vasodilation. The goal of this study was to determine whether CRP also affects endothelial arachidonic acid (AA)-prostanoid pathways for vasomotor regulation. Porcine coronary arterioles were isolated and pressurized for vasomotor study, as well as for molecular and biochemical analysis. AA elicited endothelium-dependent vasodilation and PGI(2) release. PGI(2) synthase (PGI(2)-S) inhibitor trans-2-phenyl cyclopropylamine blocked vasodilation to AA but not to serotonin (endothelium-dependent NO-mediated vasodilator). Intraluminal administration of a pathophysiological level of CRP (7 microg/mL, 60 min) attenuated vasodilations to serotonin and AA but not to nitroprusside, exogenous PGI(2), or hydrogen peroxide (endothelium-dependent PGE(2) activator). CRP also reduced basal NO production, caused tyrosine nitration of endothelial PGI(2)-S, and inhibited AA-stimulated PGI(2) release from arterioles. Peroxynitrite scavenger urate failed to restore serotonin dilation, but preserved AA-stimulated PGI(2) release/dilation and prevented PGI(2)-S nitration. NO synthase inhibitor L-NAME and superoxide scavenger TEMPOL also protected AA-induced vasodilation. Collectively, our results suggest that CRP stimulates superoxide production and the subsequent formation of peroxynitrite from basal released NO compromises PGI(2) synthesis, and thus endothelium-dependent PGI(2)-mediated dilation, by inhibiting PGI(2)-S activity through tyrosine nitration. By impairing PGI(2)-S function, and thus PGI(2) release, CRP could promote endothelial dysfunction and participate in the development of coronary artery disease.

Serum B-type natriuretic peptide on admission can predict the 'no-reflow' phenomenon after primary drug-eluting stent implantation for ST-segment elevation myocardial infarction

BACKGROUND

The angiographic 'no-reflow' phenomenon after primary percutaneous coronary intervention (PPCI) is associated with a poor short-term and long-term clinical prognosis of ST-elevation myocardial infarction (STEMI). Although the increasing use of primary drug-eluting stent (DES) deployment for STEMI resulted in reduced adverse clinical outcomes, the prevalence of no-reflow has been unchanged. The purpose of our study was to evaluate the predictors for no-reflow for STEMI and identify such high-risk patients in the DES era.

METHODS

The study prospectively enrolled 300 consecutive STEMI patients (80% men; 57+/-11 years) who underwent PPCI within 12 h of symptom onset. The no-reflow phenomenon was defined as an angiographic outcome of Thrombolysis In Myocardial Infarction (TIMI) grade <3 without accompanying mechanical factors.

RESULTS

Compared to normal reflow patients, no-reflow patients (n=15, 5% of the total study population) were older (64+/-13 vs. 57+/-11 years; P=0.019), transferred to hospital later (7.1+/-3.2 vs. 4.5+/-3.8 h; P=0.011), and had a higher TIMI risk score (5.5+/-2.0 vs. 3.8+/-2.2; P=0.004). B-type natriuretic peptide (BNP), high sensitivity C-reactive protein, and serum creatinine levels were higher in the no-reflow than the normal reflow group. Multivariate analysis (including clinical, angiographic and procedural variables with a P<0.2 in univariate analysis) showed that high BNP level on admission was the only independent predictor of no-reflow. The area under the receiver-operating characteristics curve analysis value for BNP was 0.786. BNP > or =90 pg/ml showed a sensitivity of 80% and a specificity of 70% for predicting no-reflow after primary DES implantation (OR 14.953, 95% CI 3.131-71.419, P=0.001).

CONCLUSIONS

Angiographic 'no-reflow' phenomenon after primary DES implantation for STEMI can be predicted by BNP levels on admission. BNP-guided approach may be useful in identifying patients at high risk of the no-reflow phenomenon after primary stenting.

Comparison of coronary flow reserve and fractional flow reserve in patients with versus without diabetes mellitus and having elective percutaneous coronary intervention and abciximab therapy (from the PREDICT Trial)

Patients with diabetes mellitus (DM) have poor long-term outcome after percutaneous coronary intervention (PCI) partly because of microvascular disease and distal embolization. Microvascular obstruction can be assessed by measuring coronary flow reserve (CFR). The Prediction of CK-MB RElease During Successful Stenting Correlating with Indicators of Microvascular ObstruCTion (PREDICT) trial compared the CFR in patients with versus without DM during PCI. Patients undergoing elective PCI were prospectively enrolled according to diabetic (n = 36) and nondiabetic (n = 36) status. All patients received drug-eluting stent with abciximab and were followed for 30-day major adverse cardiac events. CFR and FFR (fractional flow reserve) before and after stenting were measured before and after intracoronary adenosine bolus. Procedural success, MB enzyme of creatine-kinase (CK-MB), troponin I, and high-sensitive C-reactive protein elevation, vascular complications, and major adverse cardiac events were not different. FFR before stenting was 0.77 +/- 0.03 in patients with DM versus 0.76 +/- 0.02 in patients without DM (p = 0.69). FFR after stenting was 0.97 +/- 0.03 and 0.99 +/- 0.01 (p = 0.26), respectively. CFR before stenting was 1.36 +/- 0.31 in patients with DM versus 1.49 +/- 0.25 in patients without DM (p = 0.064). However, CFR after stenting was significantly lower in patients with versus without DM (1.89 +/- 0.30 versus 2.44 +/- 0.67, p <0.001, respectively). CFR after stenting only moderately correlated with CK-MB and high-sensitive C-reactive protein after PCI but did not correlate with 30-day major adverse cardiac events. In conclusion, patients with DM have significantly lower CFR after stenting despite equivalent FFR and myonecrosis compared with patients without DM, indicating greater microvascular obstruction after PCI despite abciximab.

Baseline systemic inflammatory status and no-reflow phenomenon after percutaneous coronary angioplasty for acute myocardial infarction

BACKGROUND

Systemic inflammation is involved in several pathological cardiovascular processes. However, whether it plays a role in the no-reflow phenomenon occurring in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI) is unknown.

METHODS

We studies 60 consecutive patients (59.5+/-12 years, 82% males) with a first ST-segment elevation AMI, treated by primary or rescue PCI within 6 h of symptom onset. Angiographic indexes of no-reflow, evaluated at the end of the procedure, included coronary TIMI flow grading, corrected TIMI frame count (c-TFC) and myocardial blush grade (MBG). ECG indexes of no-reflow included the lack of ST segment resolution (defined as a reduction <50% of the measured ST-segment elevation at 90 min, compared to the admission ECG), as analyzed both in the single lead with the maximal ST elevation and in all leads showing ST elevation on admission. Patients were divided into two groups according to baseline high-sensitivity C-reactive protein (CRP) serum levels measured on admission: high CRP group (CRP>5 mg/L) and low CRP group (CRP<5 mg/L).

RESULTS

A similar prevalence of final TIMI flow<3 and MBG<3 was observed in patients with high and low CRP serum levels (30% vs. 12%, p=0.1, and 50% vs. 53%, p=1.0, respectively), and c-TFC was also similar in the two groups (26+/-4.5 vs. 24+/-6, p=0.5). Accordingly, the prevalence of lack of ST-segment resolution in the two groups was similar, both by the single-lead method (25% vs. 25%, p=1.0) and the multiple-lead method (29% vs. 19%, p=0.4).

CONCLUSION

In this study we failed to demonstrate any significant association between CRP serum levels on admission and coronary no-reflow, as assessed by both angiographic and ECG parameters in AMI patients treated by successful primary or rescue PCI within 6 h of chest pain onset.