Clinical, angiographic and echocardiographic correlates of epicardial and microvascular spasm in patients with myocardial ischaemia and non-obstructive coronary arteries.

BACKGROUND: Coronary vasomotor dysfunction represents an important mechanism responsible for myocardial ischaemia in patients with non-obstructive coronary artery disease (CAD). The use of invasive provocative tests allows identifying patients with epicardial or microvascular spasm. Of note, clinical characteristics associated with the occurrence of epicardial or microvascular spasm have still not completely clarified. METHODS AND RESULTS: We prospectively enrolled consecutive patients undergoing coronary angiography for suspected myocardial ischaemia/necrosis with evidence of non-obstructive CAD and undergoing intracoronary provocative test for suspected vasomotor dysfunction. Patients with a positive provocative test were enrolled. Clinical, echocardiographic and angiographic characteristics of patients were evaluated according to the pattern of vasomotor dysfunction (epicardial vs. microvascular spasm). We included 120 patients [68 patients with stable angina and 52 patients with myocardial infarction and non-obstructive coronary arteries (MINOCA)]. In particular, 77 (64.2%) patients had a provocative test positive for epicardial spasm and 43 (35.8%) patients for microvascular spasm. Patients with epicardial spasm were more frequently males, smokers, had higher rates of diffuse coronary atherosclerosis at angiography and more frequently presented with MINOCA. On the other hand, patients with microvascular spasm presented more frequently diastolic dysfunction. At multivariate logistic regression analysis male sex, smoking, and diffuse coronary atherosclerosis were independent predictors for the occurrence of epicardial spasm. CONCLUSIONS: Our study showed that specific clinical features are associated with different responses to intracoronary provocative test. Epicardial spasm is more frequent in males and in MINOCA patients, whereas microvascular spasm is more frequent in patients with stable angina and is associated with diastolic dysfunction.

Coronary Atherosclerotic Phenotype and Plaque Healing in Patients With Recurrent Acute Coronary Syndromes Compared With Patients With Long-term Clinical Stability: An In Vivo Optical Coherence Tomography Study.

Importance: At one end of the coronary artery disease (CAD) spectrum, there are patients with multiple recurrent acute coronary syndromes (rACS), and at the other end there are those with long-standing clinical stability. Predicting the natural history of these patients is challenging because unstable plaques often heal without resulting in ACS. Objective: To assess in vivo the coronary atherosclerotic phenotype as well as the prevalence and characteristics of healed coronary plaques by optical coherence tomography (OCT) imaging in patients at the extremes of the CAD spectrum. Design, Setting, and Participants: This is an observational, single-center cohort study with prospective clinical follow-up. From a total of 823 consecutive patients enrolled in OCT Registry of the Fondazione Policlinico A. Gemelli-IRCCS, Rome, Italy, from March 2009 to February 2016, 105 patients were included in the following groups: (1) patients with rACS, defined as history of at least 3 acute myocardial infarctions (AMIs) or at least 4 ACS with at least 1 AMI; (2) patients with long-standing stable angina pectoris (ls-SAP), defined as a minimum 3-year history of stable angina; and (3) patients with a single unheralded AMI followed by a minimum 3-year period of clinical stability (sAMI). Data were analyzed from January to August 2018. Exposures: Intracoronary OCT imaging of nonculprit coronary segments. Main Outcomes and Measures: Coronary plaque features and the prevalence of healed coronary plaques in nonculprit segments as assessed by intracoronary OCT imaging. Results: Of 105 patients, 85 were men (81.0%); the median (interquartile range) age was 68 (63-75) years. Median (interquartile range) time of clinical stability was 9 (5.0-15.0) years in the ls-SAP group and 8 (4.5-14.5) years in the sAMI group. Patients in the rACS and sAMI groups showed similar prevalence of lipid-rich plaque and thin-cap fibroatheroma, which was significantly higher than in those with ls-SAP (lipid-rich plaque 80.0% [n = 24 of 30] vs 76.3% [n = 29 of 38] vs 37.8% [n = 14 of 37], respectively; P < .001; thin-cap fibroatheroma 40.0% [n = 12 of 30] vs 34.2% [n = 13 of 38] vs 8.1% [n = 3 of 37], respectively; P = .006). Spotty calcifications were more frequently observed in patients with rACS than in those with ls-SAP and sAMI (70.0% [n = 21 of 30] vs 40.5% [n = 15 of 37] vs 44.7% [n = 17 of 38], respectively; P = .04). Healed coronary plaques were rarely observed in patients with rACS, whereas their prevalence was significantly higher in patients with ls-SAP and sAMI (3.3% [n = 1 of 30] vs 29.7% [n = 11 of 37] vs 28.9% [n = 11 of 38], respectively; P = .01). Conclusions and Relevance: Patients with rACS have a distinct atherosclerotic phenotype compared with those with ls-SAP, including higher prevalence of thin-cap fibroatheroma and lower prevalence of healed coronary plaques, suggesting that atherosclerotic profile and plaque healing may play a role in leading the natural history of patients with CAD.

Association of PCSK9 with platelet reactivity in patients with acute coronary syndrome treated with prasugrel or ticagrelor: The PCSK9-REACT study.

BACKGROUND: Circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) enzyme might be associated with increased activation of platelets. We aimed to assess the relationship between PCSK9 levels, platelet reactivity and ischemic outcomes. METHODS: Consecutive ACS patients receiving prasugrel or ticagrelor and undergoing percutaneous coronary intervention (PCI) were enrolled in a prospective, observational study. Adenosine diphosphate (ADP)-induced platelet aggregation was determined by Multiplate Analyzer in the maintenance phase of treatment with prasugrel or ticagrelor. Major adverse cardiovascular events (MACEs) defined as composite of cardiovascular death, myocardial infarction, unstable angina, stent thrombosis, repeat revascularization, ischemic stroke were evaluated at 12months. RESULTS: A direct association was found between increased PCSK9 serum levels and platelet reactivity (r=0.30; p=0.004). When assessed according to tertile values of PCSK9, there was a significant increase in platelet reactivity in the upper vs lower tertile (p=0.02). Clinical outcome was available at follow-up in 178 subjects. In the upper PCSK9 tertile 13/59 (22.03%) patients experienced a clinical MACE at one year, vs 2/59 (3.39%) patients in the lower PCSK9 tertile. At one-year follow-up, PCSK9 was independently associated with increased ischemic MACEs: hazard ratio for upper vs lower PCSK9-level tertile was 2.62 (95% confidence interval 1.24-5.52; p=0.01). CONCLUSIONS: These findings suggest that increased PCSK9 levels are associated with higher platelet reactivity and are a possible predictor of ischemic events in ACS patients undergoing PCI.

Optimal duration of dual antiplatelet therapy after percutaneous coronary intervention with drug eluting stents: meta-analysis of randomised controlled trials.

OBJECTIVE: To assess the benefits and risks of short term (<12 months) or extended (>12 months) dual antiplatelet therapy (DAPT) versus standard 12 month therapy, following percutaneous coronary intervention with drug eluting stents. DESIGN: Meta-analysis of randomised controlled trials. DATA SOURCES: PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, Scopus, Web of Science, Cochrane Library, and major congress proceedings, searched from 1 January 2002 to 16 February 2015. REVIEW METHODS: Trials comparing short term (<12 months) or extended (>12 months) DAPT regimens with standard 12 month duration of therapy. Primary outcomes were cardiovascular mortality, myocardial infarction, stent thrombosis, major bleeding, and all cause mortality. RESULTS: 10 randomised controlled trials (n=32,287) were included. Compared to 12 month DAPT, a short term course of therapy was associated with a significant reduction in major bleeding (odds ratio 0.58 (95% confidence interval 0.36 to 0.92); P=0.02) with no significant differences in ischaemic or thrombotic outcomes. Extended versus 12 month DAPT yielded a significant reduction in the odds of myocardial infarction (0.53 (0.42 to 0.66); P<0.001) and stent thrombosis (0.33 (0.21 to 0.51); P<0.001), but more major bleeding (1.62 (1.26 to 2.09); P<0.001). All cause but not cardiovascular death was also significantly increased (1.30 (1.02 to 1.66); P=0.03). CONCLUSIONS: Compared with a standard 12 month duration, short term DAPT (<12 months) after drug eluting stent implementation yields reduced bleeding with no apparent increase in ischaemic complications, and could be considered for most patients. In selected patients with low bleeding risk and very high ischaemic risk, extended DAPT (>12 months) could be considered. The increase in all cause but not cardiovascular death with extended DAPT requires further investigation.

Sodium bicarbonate plus N-acetylcysteine to prevent contrast-induced nephropathy in primary and rescue percutaneous coronary interventions: the BINARIO (BIcarbonato e N-Acetil-cisteina nell'infaRto mIocardico acutO) study.

AIMS: Contrast-induced nephropathy (CIN) is a frequent and potentially harmful complication of percutaneous coronary interventions (PCI), especially in the setting of ST-elevation myocardial infarction (STEMI). We tested the efficacy of a sodium bicarbonate (SB)-based hydration in urgent PCI for STEMI. METHODS AND RESULTS: From June 2009 to September 2010, 262 consecutive STEMI patients undergoing urgent PCI were prospectively enrolled and treated by SB-based hydration (154 mEq/L at 3 ml Kg-1 for one hour followed by 1 ml Kg-1 for six hours) (group A). As controls, 262 consecutive STEMI patients receiving 0.9% saline hydration (1 ml Kg-1 for 24 hours) before June 2009 were retrospectively enrolled (group B). Both groups received high-dose N-acetylcysteine (NAC). The primary endpoint was the composite of in-hospital death, need for dialysis and CIN (≥25% increase in serum creatinine at 48 hours). The two groups were comparable for baseline clinical and procedural characteristics, for Mehran risk score and baseline estimated glomerular filtration rate. The primary combined endpoint was significantly reduced in group A as compared to group B (9.2 vs. 18.7%, p=0.023) with a number needed to treat (NNT) of 11. Specifically, a significant reduction of both in-hospital death (2.3 vs. 6.1%, p=0.049, NNT 27) and CIN (8.0 vs. 14.1%, p=0.03, NNT 17) was observed, with no difference in the need for dialysis. CONCLUSIONS: Our data indicate that hydration with sodium bicarbonate in addition to high-dose NAC in the setting of urgent PCI for STEMI is associated with a net clinical benefit.

Adenosine improves post-procedural coronary flow but not clinical outcomes in patients with acute coronary syndrome: a meta-analysis of randomized trials.

AIMS: Adjunctive therapy with adenosine has been shown to improve coronary flow in patients with acute coronary syndromes (ACS); it is unclear, however, whether adenosine can effectively reduce adverse clinical events. The aim of our study was to perform a meta-analysis of all randomized controlled trials (RCTs) investigating angiographic and clinical outcomes in ACS patients undergoing PCI or thrombolysis and receiving adjunctive adenosine therapy vs. placebo. METHODS: Medline/CENTRAL/EMBASE and Google Scholar database were scanned. The meta-analysis included ten RCTs (N=3821). All-cause mortality was chosen as primary endpoint. Secondary endpoints were re-infarction (MI), heart failure (HF) symptoms (NYHA class III/IV), no-reflow (defined as TIMI 0 flow) and >50% ST-resolution. RESULTS: Adenosine compared to placebo was associated with a significant reduction of post-procedural no-reflow (OR [95% CI]=0.25 [0.08-0.73], p=0.01); however, at a median follow-up of 6 months, prior treatment with adenosine did not confer significant benefits in terms of reduction of mortality (OR(Fixed) [95% CI]=0.87 [0.69-1.09], p=0.23), as well as re-MI (p=0.80), HF symptoms (p=0.44) and ST-resolution (p=0.09). Separate analyses conducted in the subgroups of ST-elevation MI patients treated with either PCI or thrombolysis confirmed the findings found in the overall population. CONCLUSIONS: This meta-analysis shows that adenosine adjunctive therapy does not improve survival nor reduce the rates of re-MI and HF symptoms in patients with ACS treated with PCI or thrombolysis. The beneficial effect on post-procedural coronary flow was not associated with consistent advantages on clinical outcomes.

Relation between stress-induced myocardial perfusion defects on cardiovascular magnetic resonance and coronary microvascular dysfunction in patients with cardiac syndrome X.

OBJECTIVES: The purpose of this study was to investigate whether a direct relation can be demonstrated between myocardial perfusion defects detected during dobutamine stress test (DST) by cardiovascular magnetic resonance (CMR) and impairment of coronary microvascular dilatory function in patients with cardiac syndrome X (CSX). BACKGROUND: Despite the fact that coronary microvascular dysfunction has been shown in most patients with CSX, the ischemic origin of CSX remains debated. No previous study assessed whether a strict relation exists between abnormalities in myocardial perfusion and coronary microvascular dysfunction in CSX patients. METHODS: Eighteen CSX patients (mean age 58 +/- 7 years, 7 men) and 10 healthy control subjects (mean age 54 +/- 8 years, 4 men) underwent myocardial perfusion study by gadolinium-enhanced CMR at rest and at peak DST (maximal dose 40 microg/kg/min). Coronary flow response (CFR) to adenosine (140 microg/kg/min in 90 s) in the left anterior descending (LAD) coronary artery was assessed by high-resolution transthoracic echo-Doppler and expressed as the ratio between coronary flow velocity at peak adenosine and at rest. RESULTS: At peak DST, reversible perfusion defects on CMR were found in 10 CSX patients (56%) but in none of the control subjects (p = 0.004). The CFR to adenosine in the LAD coronary artery was lower in CSX patients than in control subjects (2.03 +/- 0.63 vs. 3.29 +/- 1.0, p = 0.0004). The CSX patients with DST-induced myocardial perfusion defects in the LAD territory on CMR had a lower CFR to adenosine compared with those without perfusion defects in the LAD territory (1.69 +/- 0.5 vs. 2.31 +/- 0.6, p = 0.01). A significant correlation was found in CSX patients between CFR to adenosine and a DST perfusion defect score on CMR in the LAD territory (r = -0.45, p = 0.019). CONCLUSIONS: Our data concurrently show DST-induced myocardial perfusion defects on CMR and reduced CFR in the LAD coronary artery territory in CSX patients, thus giving strong evidence that a dysfunction of coronary microcirculation resulting in myocardial perfusion abnormalities is present in these patients.

Coronary vasospasm secondary to hypercholinergic crisis: an iatrogenic cause of acute myocardial infarction in myasthenia gravis.

Patients with myasthenia gravis undergo lifelong treatment with anticholinesterase agents. While the heart is usually unaffected by this disease, clinicians should bear in mind the potential adverse interaction between cardiac function and the underlying myasthenic disease or its specific medications. In the present article we report, to the best of our knowledge for the first time in the literature, a case of vasospastic acute myocardial infarction due to iatrogenic hypercholinergic crisis secondary to anticholinesterase therapy in an elderly female with myasthenia gravis. This clinical vignette emphasizes the importance of taking into account the potential vasospastic effect of anticholinesterase drugs. Indeed, prompt recognition of the pathophysiology of myocardial ischemia due to iatrogenic hypercholinergic crisis is pivotal to the timely and appropriate management of this medical emergency, as well as prevention of future recurrences.