Teresa Alvarado

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.

Noninvasive diagnosis of vulnerable coronary plaque

Myocardial infarction and sudden cardiac death are frequently the first manifestation of coronary artery disease. For this reason, screening of asymptomatic coronary atherosclerosis has become an attractive field of research in cardiovascular medicine. Necropsy studies have described histopathological changes associated with the development of acute coronary events. In this regard, thin-cap fibroatheroma has been identified as the main vulnerable coronary plaque feature. Hence, many imaging techniques, such as coronary computed tomography, cardiac magnetic resonance or positron emission tomography, have tried to detect noninvasively these histomorphological characteristics with different approaches. In this article, we review the role of these diagnostic tools in the detection of vulnerable coronary plaque with particular interest in their advantages and limitations as well as the clinical implications of the derived findings.

Diagnostic accuracy of a hybrid approach of instantaneous wave-free ratio and fractional flow reserve using high-dose intracoronary adenosine to characterize intermediate coronary lesions: Results of the PALS (Practical Assessment of Lesion Severity) prospective study

We sought to investigate the diagnostic accuracy of instantaneous wave‐free ratio (iFR) and high‐dose intracoronary adenosine fractional flow reserve (IC‐FFR) compared with classical intravenous adenosine fractional flow reserve (IV‐FFR) to assess coronary stenosis severity. The usefulness of two hybrid strategies combining iFR and high‐dose IC‐FFR was also evaluated. Background: Physiological assessment of intermediate coronary stenoses to guide revascularization is currently recommended. Methods: Consecutive real‐world patients with angiographically intermediate coronary stenosis (40–80% diameter stenosis) were prospectively included in the PALS (Practical Assessment of Lesion Severity) study. In every target lesion iFR, high‐dose IC‐FFR and IV‐FFR were systematically measured to assess the accuracy of an hybrid sequential approach combining iFR and IC‐FFR. Results: A total of 106 patients with 121 intermediate coronary lesions were analyzed. Both, iFR and IC‐FFR showed a significant correlation with IV‐FFR (iFR: r = 0.60, 95%CI 0.48–0.70; IC‐FFR: r = 0.88; 95%CI: 0.83–0.92). High‐dose IC‐FFR provided lower FFR values than IV‐FFR (0.81 ± 0.08 vs. 0.82 ± 0.09, P = 0.25). Using a receiver‐operating‐characteristic curve an optimal iFR threshold of 0.91 for the screening test was identified. A sequential test strategy (initial iFR followed by IC‐FFR only in lesions with iFR <0.91) yielded an excellent diagnostic accuracy (96.7%, 95%CI 96.7–99.1%) with a sensitivity, specificity, positive and negative predicted values of 100%, 94.7%, 91.8%, and 100%, respectively. A hybrid approach using the previously described iFR gray zone (0.85–0.94) also provided an excellent diagnostic accuracy (95%, 95%CI: 89.5–98.1%). Conclusions: In patients with intermediate coronary lesions a hybrid strategy by using a sequential approach of iFR and high‐dose IC‐FFR, provided a very good diagnostic performance to identify physiologically significant stenoses.

Bioresorbable vascular scaffolds in patients with acute myocardial infarction: a new step forward to optimized reperfusion?

Bioresorbable vascular scaffolds (BVS) represent a disruptive technology that has caused a new revolution in interventional cardiology. BVS appear to be particularly appealing in patients presenting with an acute myocardial infarction (MI). The available evidence on the value of BVS implantation in this challenging scenario is very promising but still limited. Results come from preliminary small observational studies, prospective registries that include a control group, and from scarce randomized clinical trials with surrogate mechanistic or angiographic primary end-points. Further studies, powered for clinical endpoints, are required to establish the relative safety and efficacy of BVS vs. new-generation metallic drug-eluting stents (DES) in patients with ST-segment elevation acute MI.

Multifaceted Presentation of Recurrent Spontaneous Coronary Artery Dissection: Angiography and Optical Coherence Tomography Findings.

A 58-year-old woman with a previous history of hypertension, hypercholesterolemia, and cigarette smoking presented with a non–ST-segment–elevation myocardial infarction with transient (nonpersistent) anterior ST-segment–elevation suggesting ischemia on the territory of the left anterior descending coronary artery. The coronary angiogram showed no signs of atherosclerosis but depicted severely tortuous coronary arteries with a focal lumen narrowing in the mid-segment of the left anterior descending coronary artery (Figure 1A). In addition, a diffuse lesion with a double lumen was demonstrated at the mid-segment of the posterior descending coronary artery branch of the right coronary artery (Figure 1B). Moreover, the distal left circumflex coronary artery also showed an image of a double lumen (Figure 1C). These findings were highly suggestive of 3-vessel spontaneous coronary artery dissection (SCAD). As the patient was stable and asymptomatic with no signs of ongoing ischemia, a conservative medical approach was selected, and she was eventually discharged on a low dose of aspirin. A control angiogram scheduled at 12 months depicted restitutio ad integrum of the left anterior descending coronary artery and posterior descending coronary artery lesions with a completely normal vessel appearance (Figure 1D and 1E). Nevertheless, the image of double lumen on the distal circumflex coronary artery remained unchanged. Figure 1. Coronary angiogram showing ( A ) focal lesion (white arrow) at the mid-segment of left anterior descending coronary artery (LAD). B , Mid-portion of …

Coronary artery aneurysm formation following implantation of a bioresorbable vascular scaffold for in-stent restenosis

Coronary artery aneurysm (CAA) formation is a rare complication of coronary intervention that may develop after implantation of bare-metal or drug-eluting stents. The etiology of this entity appears to be multifactorial and its prognosis is poorly understood, but it has been associated with an increased risk of stent thrombosis. To date few cases of CAAs related to bioresorbable vascular scaffold (BVS) implantation have been reported, and the development of CAA after BVS implantation for the treatment of in-stent restenosis (ISR) has not been previously described. Here we present two cases of CAA formation after BVS, which represent the first demonstration of CAA formation after the use of BVS for ISR.

Optical Coherence Tomography Findings in Patients With Recanalized Coronary Thrombi Treated With Bioresorbable Vascular Scaffolds

Recanalized coronary thrombi (RCT) are rarely recognized in real-world clinical practice. Incidence and functional significance of RCT remain unclear. High-resolution imaging modalities, such as optical coherence tomography (OCT), may provide novel insight to further characterize this unique phenomenon.1,2 We present a case series of RCT treated with bioresorbable vascular scaffold (BVS). A 75-year-old man with a previous history of an inferior myocardial infarction was admitted with congestive heart failure. Inferior hypokinesia was detected on echocardiography. Coronary angiography showed a filling defect and luminal haziness in the proximal segment of the right coronary artery (Figure 1A). OCT revealed multiple diaphragm-like membranes dividing the lumen into multiple small channels with a Lotus root or Swiss-cheese appearance (Figure …

Coronary fistula as an arteriovenous malformation behind the left atrium. Untightening the tangle with cardiac CT.

An 80-year-old man was followed for several years in outpatient clinic due to stable angina. Basal ECG revealed the left anterior fascicular and right-bundle branch blockswithout other relevant changes. Normal global and segmental contractility were confirmed on echocardiogram, with no other findings. For further evaluation, a dobutamine stress test was performed that did not showany sign of ischemia on ECG and echocardiogram, although the patient referred chest tightness during the recovery phase. A subsequent exercise SPECT study demonstrated a fixed inferoapical perfusion defect, which was interpreted as an artifact. Due to persistence of angina in spite of optimal medical treatment, the patient was referred to the catheterization laboratory. The coronary angiography (CA) demonstrated severe stenoses in the proximal and mid left anterior descending (LAD) artery (Fig. 1, Panel A, arrow heads),with non-significant atherosclerosis in the rest of the vessels. Contrast injection in the left coronary artery revealed 3 vascular structures that seem to arise from the left main (LM), and medium and distal segments of left circumflex (LCX), and have multiple connections with no clear drainage (Fig. 1, Panels A to C). Both LAD lesions were treatedwith drug eluting stents and a cardiac computed tomography (CCT) was requested for further characterization of the coronary vascular anomaly.