Paula Antuña

Spontaneous coronary artery dissection: new insights into diagnosis and treatment.

Spontaneous coronary artery dissection (SCAD) remains an infrequent, elusive, and challenging clinical entity of unknown etiology eight decades after its initial description. Our understanding of the pathophysiology of SCAD, initially limited to information from early pathological studies, case reports, and very short series, has been enriched recently by relatively large contemporary series of patients studied prospectively. The typical presentation involves a young woman without coronary risk factors suffering an acute coronary syndrome but, actually, most patients are middle-aged and have coronary risk factors. A high number of conditions have been related to SCAD, but fibromuscular dysplasia has shown a major intriguing association with potential pathophysiological implications. SCAD may present (a) with an intimal tear and the classic angiographic ‘flap’ leading to the appearance of two lumens (true and false), or (b) without an intimal rupture, as an intramural hematoma. An increased clinical awareness together with new diagnostic tools have led to a major surge in the diagnosis of SCAD. High-resolution intracoronary techniques provide unique diagnostic insights into the underlying pathophysiology and facilitate identification of the disease in patients misdiagnosed previously. After the initial acute ischemic insult, most patients stabilize and have a benign clinical course and eventually experience spontaneous healing of the vessel wall during follow-up. However, recurrences may still occur in up to 10–20% of cases. Accordingly, a conservative medical management (watchful waiting strategy) has been recommended as the initial approach. Revascularization remains particularly challenging and may be associated with suboptimal results, acute complications, and poor long-term outcome. Nevertheless, in patients with ongoing or refractory ischemia and adequate anatomy, revascularization should be attempted. Some novel and attractive coronary interventions have been proposed in this uniquely challenging anatomic scenario. This review aims to present a comprehensive and contemporary update on this elusive and intriguing clinical entity.

Optical Coherence Tomography Findings in Patients With Stent Thrombosis

INTRODUCTION AND OBJECTIVES Stent thrombosis (ST) is a rare but potentially serious complication. Optical coherence tomography (OCT) provides high-resolution images and additional information to angiography in the study of this event. METHODS Prospective study of patients with ST undergoing reintervention with OCT imaging. RESULTS The study included a total of 40 consecutive patients with ST. Mean age was 69 ± 13 years and 83% were male. Early ST (≤ 30 days) was observed in 16 patients and late ST (> 30 days) in 24 patients. Stent thrombosis occurred in 17 bare-metal stents and 23 drug-eluting stents. In 34 patients (85%), adequate OCT images were obtained at the time of the ST. The predominant mechanism in early ST was stent malapposition (39%). In late ST, high frequencies of uncovered (46%) and malapposed struts (17%) were observed, especially in patients with drug-eluting stents. Furthermore, the presence of neoatherosclerosis was very high (67%) in patients with late ST. After intervention, improvements were observed in malapposition length and the amount of residual thrombus. CONCLUSIONS OCT allows identification of the underlying mechanisms potentially involved in ST. This imaging modality is helpful in guiding reintervention in these patients, which improves the area and length of malapposition, as well as the maximal residual thrombus area.

Time-Related Microcirculatory Dysfunction in Patients With Takotsubo Cardiomyopathy

This study assesses whether there is a time-dependent trend in microvascular damage in patients presenting with takotsubo cardiomyopathy by invasively measuring the index of microvascular resistance.

Reliability of physiological assessment of coronary stenosis severity using intracoronary pressure techniques: a comprehensive analysis from a large cohort of consecutive intermediate coronary lesions

AIMS We sought to assess the reliability of the most frequently used intracoronary physiologic indices (including intravenous adenosine FFR [IV-FFR], intracoronary low-dose adenosine FFR [LD-IC-FFR], intracoronary high-dose adenosine FFR [HD-IC-FFR], Pd/Pa and iFR). We also sought to analyse factors affecting their reproducibility in a real-world patient population. METHODS AND RESULTS A total of 91 lesions in 86 consecutive patients were included. Measurements of all physiological indices were repeated within a systematic standardised prospective protocol. All measured indices showed excellent test-retest reliability, with intraclass correlation coefficient (ICC) over 0.96. IV-FFR showed the highest coefficient of variation (CV) values among the studied measurements (Pd/Pa: 0.05; iFR: 0.10; LD-IC-FFR: 0.10; HD-IC-FFR: 0.08; IV-FFR: 0.12). Pd/Pa was significantly less variable than the other indices. On multivariate analysis, female gender, distal lesion location, history of hypertension or kidney failure, as well as presentation as an acute coronary syndrome, were associated with more variability in all physiological intracoronary measurements. CONCLUSIONS The reliability of most frequently used intracoronary physiologic indices is high. Clinical and anatomic factors significantly influence the reliability of these physiologic indices.

Coronary Pleating Mimicking Coronary Ruptures, Dissections, and Thrombi on Optical Coherence Tomography

Straightening of tortuous coronaries by intracoronary guidewires may generate intimal wrinkles or coronary pleating and lead to the development of different abnormal angiographic findings widely known as pseudostenosis or accordion effect.1 We report the unique findings disclosed by optical coherence tomography (OCT) in 3 patients developing coronary pleating. An 84-year-old woman with severe aortic stenosis was referred for coronary angiography before transcatheter aortic valve implantation. A severe stenosis in the mid segment of the right coronary artery was treated with a bare metal stent. The guidewire induced a new moderate focal lesion at the most proximal segment of this vessel (Figure 1A). OCT revealed images consistent with a ruptured plaque with a large cavity adjacent to a normal coronary wall and also images suggesting a large lipid plaque (Figure 1B–1E). Once the guidewire was removed, the angiographic pseudostenosis completely disappeared (Figure 1F) confirming the occurrence of an accordion effect. Figure 1. A , Angiographic images of …

Acute myocardial infarction in a young woman on isotretinoin treatment

The use of isotretinoin has been associated with mild changes in the metabolic profile of adolescents. In very rare cases, a possible association with myocardial infarction, stroke and thromboembolic events has been reported. In this report we describe the potential association of isotretinoin with the occurrence of an acute myocardial infarction in a very young girl. OCT provided unique visualization of the culprit lesion.

Spontaneous coronary artery dissection: from expert consensus statements to evidence-based medicine

Spontaneous coronary artery dissection (SCAD) represents an increasingly recognized cause of acute coronary syndrome (ACS), especially in young females. Novel diagnostic insights obtained from intracoronary imaging and the frequent association with fibromuscular dysplasia (FMD), have recently enriched our understanding of this unique clinical entity. Recently, two scientific statements from both sides of the Atlantic, summarizing the available information on SCAD, have been simultaneously published. These should help to guide the clinical management of these challenging patients. Major collaborative research efforts are required to move from expert-based recommendations to evidence-base medicine.

Early restenosis of resorbable magnesium scaffolds: Optical coherence tomography findings

Resorbable Magnesium Scaffolds (RMS) represent an interesting alternative to current drug‐eluting stents. Current data from clinical trials seems to confirm good performance of these new devices with low rates of late device failure. Little is known about mechanisms leading to RMS failure. Herein, we present the first description of an early RMS in‐scaffold restenosis. Optical coherence tomography (OCT) analysis at implantation detected acute non‐severe malapposition and underexpansion as main promoters of RMS failure. OCT during in‐scaffold restenosis intervention confirmed early severe neointimal proliferation and RMS late recoil and dismantling as the main mechanisms of device failure. We hypothesize that the fast resorption process of RMS may lead to an early loss of radial strength, that could favor late recoil, acquired underexpansion, device dismantling and might interact with distribution of sirolimus. This case also illustrates that OCT is pivotal to unravel both acute and acquired mechanisms related to RMS failure.