Extrinsic compression of left main coronary artery by aneurysmal pulmonary artery in severe pulmonary hypertension: its correlates, clinical impact, and management strategies

Left main coronary artery compression in precapillary pulmonary hypertension

Pulmonary hypertension (PH) is a progressive and invalidating condition despite available therapy. Addressing complications such as left main coronary artery compression (LMCo) due to the dilated pulmonary artery (PA) may improve symptoms and survival. Nevertheless, clear recommendations are lacking. The aim of this study is to analyze the prevalence, characteristics, predictive factors and impact of LMCo in a heterogenous precapillary PH population in a single referral center. Two hundred sixty-five adults with various etiologies of precapillary PH at catheterization were reviewed. Coronary angiography (CA) was performed for LMCo suspicion. Revascularization was performed in selected cases. Outcomes were assessed at a mean follow-up of 3.9 years. LMCo was suspected in 125 patients and confirmed in 39 (31.2%), of whom 21 (16.8%) had 50%-90% stenoses. Nine revascularizations were performed, with clinical improvement. The only periprocedural complication was a stent migration. LMCo was associated with PH etiology (p 0.003), occuring more frequently in congenital heart disease-associated PH (61.5% of all LMCo cases, 66.6% of LMCo ≥ 50%). Predictors of LMCo ≥50% were PA ≥ 37.5 mm (Sn 81%, Sp 74%) and PA-to-aorta ≥1.24 (Sn 81%, Sp 69%), with increased discrimination when considering RV end-diastolic area. LMCo ≥ 50% without revascularization presented clinical deterioration and worse survival (p 0.019). This analysis of a heterogeneous pre-capillary PH population provides LMCo prevalence estimation, predictive factors (PA size, PA-to-aorta, RV end-diastolic area and PH etiology) and long-term impact. While LMCo impact on survival is inconclusive, untreated LMCo ≥ 50% has worse prognosis. LMCo revascularization may be performed safely and with good outcomes.

Medical Emergencies in Pulmonary Hypertension

The management of acute medical emergencies in patients with pulmonary hypertension (PH) can be challenging. Patients with preexisting PH can rapidly deteriorate due to right ventricular decompensation when faced with acute physiological challenges that would usually be considered low-risk scenarios. This review considers the assessment and management of acute medical emergencies in patients with PH, encompassing both pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), acknowledging these comprise the more severe groups of PH. Management protocols are described in a systems-based approach. Respiratory emergencies include pulmonary embolism, airways disease, and pneumonia; cardiac emergencies including arrhythmia and chest pain with acute myocardial infarction are discussed, alongside PH-specific emergencies such as pulmonary artery dissection and extrinsic coronary artery compression by a dilated proximal pulmonary artery. Other emergencies including sepsis, severe gastroenteritis with dehydration, syncope, and liver failure are also considered. We propose management recommendations for medical emergencies based on available evidence, international guidelines, and expert consensus. We aim to provide advice to the specialist alongside the generalist, and emergency doctors, nurses, and acute physicians in nonspecialist centers. A multidisciplinary team approach is essential in the management of patients with PH, and communication with local and specialist PH centers is paramount. Close hemodynamic monitoring during medical emergencies in patients with preexisting PH is vital, with early referral to critical care recommended given the frequent deterioration and high mortality in this setting.

Treatment of left main coronary artery compression in the setting of unpalliated congenital heart disease: a case series

Background

Left main coronary artery compression syndrome (LMCS) is a well-characterized phenomenon resulting from compression of the left main coronary artery (LMCA) between the aorta and an enlarged pulmonary arterial trunk. The development of LMCS is usually described in the context of severe pulmonary arterial hypertension. Cases of LMCS, in the context of unpalliated congenital heart disease (CHD), are complex clinical scenarios that challenge traditional treatment paradigms.

Case summary

Here, we discuss two thought-provoking patients with unpalliated CHD complicated by severe pulmonary hypertension (PH). Both patients developed LMCS, one with severe non-ST elevation myocardial infarction and the other with refractory angina. Their pulmonary vascular resistance was severely elevated despite pulmonary vasodilator therapy, and concomitant surgical correction of their CHD in addition to bypass grafting was deemed high risk. They underwent successful percutaneous coronary intervention (PCI) of the LMCA with drug-eluting stents.

Discussion

Pulmonary hypertension can develop in the setting of long-standing unpalliated CHD. Surgical correction of congenital heart defects may be performed in select patients with systemic-to-pulmonary shunts, contingent on the status of PH severity. Pulmonary vasodilator therapy modulates haemodynamics to ensure surgical correction without risk of cardiopulmonary demise-termed the 'treat and repair' strategy. LMCS, an increasingly recognized phenomenon in patients with long-standing PH, is a notable complicating factor in the 'treat and repair' strategy. We introduce the concept that PCI of the LMCA may bridge patients to corrective surgery for CHD by allowing time for optimization of their pulmonary vasodilator therapy.

Stenosis of the trunk of the left coronary artery in idiopathic pulmonary hypertension. Case report

The manuscript presents a clinical case of treatment of a patient with idiopathic pulmonary hypertension and a rare complication left main coronary artery stenosis caused due to compression by the dilated pulmonary artery. This complication was clinically manifested by chest pain. The patient underwent percutaneous coronary angioplasty with stenting of the left main coronary artery and subsequent prescription of combined PAH-specific therapy. During the late follow-up examination in addition to clinical improvement and the absence of pain, 6-minute walking test distance increase, positive dynamics of echocardiography, right heart catheterization, as well as the laboratory marker of heart failure NT-proBNP were noted.

ACR Appropriateness Criteria® Suspected Pulmonary Hypertension: 2022 Update

Pulmonary hypertension may be idiopathic or related to a large variety of diseases. Various imaging examinations may be helpful in diagnosing and determining the etiology of pulmonary hypertension. Imaging examinations discussed in this document include chest radiography, ultrasound echocardiography, ventilation/perfusion scintigraphy, CT, MRI, right heart catheterization, and pulmonary angiography. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Congenital Absence of the Portal Vein as a Rare Cause of Portopulmonary Hypertension-A Case Study Series

Background. Congenital absence of the portal vein (CAPV) is an extremely rare malformation that is caused by aberrant venous development during embryogenesis and is usually associated with congenital portosystemic shunts (CPSS). This hemodynamic allows mesenteric blood to bypass the liver metabolism and causes an imbalance between vasodilators and vasoconstrictors in the pulmonary circulation, which, again, might lead to the development of secondary portopulmonary hypertension (PoPH). Establishing the exact morphology of the splanchnic venous system is important when evaluating possible therapeutic options (differentiating type I and II CAPV), because some variants enable the closure of the shunt, and this represents a potential cure for pulmonary arterial hypertension (PAH). Once PoPH is diagnosed, complex care in a specialized expert centre is necessary. If possible, CPSS closure is recommended. For long-term successful patient management, specific targeted PAH therapy administration is crucial. Significant morbidity and mortality in these patients may result not only from PAH itself but also due to specific PoPH complications, such as compression of the left main coronary artery by pulmonary artery aneurysm. Case Report. We report on two patients with PoPH due to CAPV and CPSS (without any liver disease) who presented as severe PAH and who, before admission to our expert centre, were misdiagnosed as idiopathic PAH. The case reports also represent our experience with respect to the long-term follow-up and PAH-specific medical treatment of these patients, as well as the possible (even fatal) complications of these rare and complex patients.

Left main coronary artery compression by dilated pulmonary artery in pulmonary arterial hypertension: a systematic review and meta-analysis

OBJECTIVE

Pulmonary arterial hypertension (PAH) can lead to left main coronary artery compression (LMCo), but data on the impact, screening and treatment are limited. A meta-analysis of LMCo cases could fill the knowledge gaps in this topic.

METHODS

Electronic databases were searched for all LMCo/PAH studies, abstracts and case reports including pulmonary artery (PA) size. Restricted maximum likelihood meta-analysis was used to evaluate LMCo-associated factors. Specificity, sensitivity and accuracy of PA size thresholds for diagnosis of LMCo were calculated. Treatment options and outcomes were summarized.

RESULTS

A total of five case-control cohorts and 64 case reports/series (196 LMCo and 438 controls) were included. LMCo cases had higher PA diameter (Hedge's g 1.46 [1.09; 1.82]), PA/aorta ratio (Hedge's g 1.1 [0.64; 1.55]) and probability of CHD (log odds-ratio 1.22 [0.54; 1.9]) compared to non-LMCo, but not PA pressure or vascular resistance. A 40 mm cut-off for the PA diameter had balanced sensitivity (80.5%), specificity (79%) and accuracy (79.7%) for LMCo diagnosis, while a value of 44 mm had higher accuracy (81.7%), higher specificity (91.5%) but lower sensitivity (71.9%). Pooled mortality after non-conservative treatment (n = 150, predominantly stenting) was 2.7% at up to 22 months of mean follow-up, with 83% survivors having no angina at follow-up.

CONCLUSION

PA diameter, PA/aorta ratio and CHD are associated with LMCo, while hemodynamic parameters are not. Data from this study support that a PA diameter cut-off between 40 and 44 mm can offer optimal accuracy for LMCo screening. Preferred treatment was coronary stenting, associated with low mid-term mortality and symptom relief. Diagnosis and management of left main coronary artery compression (LMCo) in patients with pulmonary arterial hypertension (PAH).

Three-Dimensional High-Resolution Temporal Bone Histopathology Identifies Areas of Vascular Vulnerability in the Inner Ear

OBJECTIVES

Hypothesized causes of vestibular neuritis/labyrinthitis include neuroinflammatory or vascular disorders, yet vascular disorders of the inner ear are poorly understood. Guided by known microvascular diseases of the retina, we developed 2 hypotheses: (1) there exist vascular vulnerabilities of artery channels in cases of hypothetical nerve swelling for the superior, inferior, and vestibulocochlear artery and (2) there are arteriovenous crossings that could compromise vascular flow in disease states.

METHODS

Two fully mounted and stained temporal bones were used to render three-dimensional reconstructions of the labyrinth blood supply. Using these maps, areas of potential vascular compression were quantified in 50 human temporal bones.

RESULTS

Although inner ear arteries and veins mostly travel within their own bony channels, they may be exposed (1) at the entrance into the otic capsule, and (2) where the superior vestibular vein crosses the inferior vestibular artery. At the entry into the otic capsule, the ratio of the soft tissue to total space for the superior vestibular artery was significantly greater than the inferior vestibular artery/cochleovestibular artery (median 44, interquartile range 34-55 vs. 14 [9-17], p < 0.0001).

CONCLUSIONS

Three-dimensional reconstruction of human temporal bone histopathology can guide vascular studies of the human inner ear. Studies of retinal microvascular disease helped identify areas of vascular vulnerability in cases of hypothetical nerve swelling at the entrance into the otic capsule and at an arteriovenous crossing near the saccular macula. These data may help explain patterns of clinical findings in peripheral vestibular lesions.

Acute Myocardial Infarction due to External Compression of the Left Main Coronary Artery by a Large Pulmonary Artery Aneurysm

Background

Although rare, external compression of the left main coronary artery (LMCA) by a pulmonary arterial aneurysm (PAA) as a consequence of pulmonary arterial hypertension causing stable angina pectoris is well described. However, acute myocardial infarction is extremely rare, particularly with a full array of electrocardiographic, biochemical, and echocardiographic features, as in this scenario.

Case

In this case, a 62-year-old man with a past history of severe fibrotic lung disease was hospitalised with chest pain. The patient had dynamic anterolateral ischaemic changes on electrocardiography and serially elevated high-sensitivity troponin I. Transthoracic echocardiography revealed impaired left ventricular ejection fraction with anterolateral hypokinesis. Coronary angiography with intracoronary imaging revealed external compression of the LMCA. Computer tomography (CT) scans confirmed new PAA, compared to previous scans. The patient was successfully treated by percutaneous coronary stent implantation.

Conclusion

Progressive dilatation of the pulmonary artery due to pulmonary arterial hypertension can result in acute MI secondary to external compression of the LMCA. Clinicians should be mindful of acute coronary syndromes in patients with long-standing pulmonary hypertension presenting with chest pain.

Clinical relevance of adding intravascular ultrasound to coronary angiography for the diagnosis of extrinsic left main coronary artery compression by a pulmonary artery aneurysm in pulmonary hypertension

OBJECTIVES

We sought to assess the clinical value of adding intravascular ultrasound (IVUS) evaluation to coronary angiography (CA) to guide extrinsic left main coronary artery (LMCA) compression diagnosis and treatment in pulmonary hypertension (PH).

BACKGROUND

LMCA compression due to a pulmonary artery aneurysm (PAA) is a severe complication of PH. Although guidelines encourage the use of IVUS for LMCA disease evaluation, it has hardly been used in this scenario.

METHODS

We analyzed morbimortality of type 1 and 4 PH patients with clinically suspected LMCA compression by a PAA between 2010 and 2018 in a reference unit. LMCA compression was prospectively assessed with CA ± IVUS. Angiographic-LMCA compression was considered conclusive when LMCA stenosis>50% was present in four predetermined projections; inconclusive, when LMCA stenosis>50% was present in <4 projections and negative if no stenosis>50% was present. Patients with conclusive and inconclusive CA underwent IVUS. IVUS-LMCA compression was defined as systolic minimum lumen area < 6 mm² .

RESULTS

LMCA compression was suspected in 23/796 patients (3%). CA was conclusive for compression in 7(30.5%), inconclusive in 9(39%), and negative in 7(30.5%). IVUS confirmed LMCA compression in 6/7(86%) patients with conclusive CA and in 2/9(22%) with inconclusive CA. Patients fulfilling IVUS criteria for LMCA compression underwent stent implantation. At 20 months follow-up a composite end-point of death, stent restenosis/thrombosis, or lung transplant was reported in three patients (13%).

CONCLUSIONS

CA can misdiagnose LMCA extrinsic compression. IVUS discriminates better whether significant compression by a PAA exists or not, avoiding unnecessary LMCA stenting. Patients treated following this strategy show a low rate of major clinical events at 20 months follow-up.

Utility of CT Angiography for the Prediction of Coronary Artery Compression in Patients Undergoing Transcatheter Pulmonary Valve Replacement

Objectives:

We aimed to evaluate the utility of computed tomography angiography (CTA) for coronary compression (CC) prediction in patients with congenital heart disease undergoing balloon-expandable transcatheter pulmonary valve replacement (TPVR).

Background:

Coronary compression is a serious complication of TPVR, but the value of preprocedural CTAs to assess CC risk is largely unexplored.

Methods:

In all, 586 patients underwent TPVR between January 2009 and July 2018. Adults with a pre-TPVR CTA and children with a CTA performed less than one year prior to TPVR were included. Patients with poor CTA image quality or with aborted cases due to reasons other than CC were excluded. Sixty-six patients were finally included. Cardiac anatomy was assessed via multiplanar reconstruction of CTAs.

Results:

Coronary compression occurred in 9 (14%) of the 66 patients who underwent TPVR. Most CC cases (seven of nine) occurred in patients with conduits. Proximity of the right ventricular outflow tract (RVOT) landing zone to the coronary arteries and to the chest wall was a significant risk factor for compression ( P < .001 and P = .019, respectively). Compression risk increased significantly if patients had an RVOT to coronary artery distance of ≤3 mm ( P < .001) and an RVOT to chest wall distance of ≤8 mm ( P = .026). Anomalous course of coronary arteries was another significant univariate risk factor ( P = .003).

Conclusions:

Right ventricular outflow tract landing zone distance of ≤3 mm to a coronary artery, landing zone distance of ≤8 mm to the chest wall, and anomalous coronary arteries are associated with increased CC risk. Electrocardiogram gating may not be necessary if coronary arteries are opacified on CTAs. Larger studies are needed to explore and confirm these coronary artery compression risk factors.

Athlete Cardiovascular Concerns in the Training Room: What Do I Do If…?

Cardiac disease can present in the training room through three portals: the preparticipation history and physical may identify concerns, the athlete may present with symptoms, or screening modalities may demonstrate abnormal findings. Training-related cardiovascular remodeling can mimic real disease, therefore providers must be able to separate the two. Sports medicine providers must be knowledgeable in how these present and how to care for these concerns to ensure proper care and avoid unnecessary restrictions of athletes. This article discusses 10 common cardiac concerns that can arise in the training room.

Left main coronary artery compression by pulmonary artery aneurism in patients with long standing pulmonary arterial hypertension

This review focuses on a rare complication of pulmonary arterial hypertension (PAH), extravasation compression of the left coronary artery (LCA) dilated by the pulmonary artery. The review described clinical manifestations and methods for diagnostics of LCA compression, and advantages of the endovascular correction of this complication in patients with pulmonary hypertension. Selection of a device to be implanted during the endovascular intervention in these patients was discussed with due account for concomitant treatment with oral anticoagulants. As an illustration of the issue under discussion, a clinical case of acute coronary syndrome in a female patient from the PAH Registry of the V. A. Almazov National Medical Research Center was provided.