The potential hazard of drug-eluting stent-induced coronary vasospasm causing subacute stent thrombosis: a case report

Severe Coronary Artery Vasospasm after Mitral Valve Replacement in a Diabetic Patient with Previous Stent Implantation: A Case Report

Postoperative coronary vasospasm is a well-known cause of angina that may lead to myocardial infarction if not treated promptly. We report a case of a 70-year-old female with severe mitral regurgitation submitted to mitral valve replacement, and a history of diabetes mellitus type II, stroke, idiopathic thrombocytopenic purpura on steroid therapy, and previous percutaneous coronary intervention (PCI) for severe obstruction of the circumflex coronary artery, 4 months prior to surgery. Immediately after intensive care unit admission, the patient developed pulseless electrical activity which required extracorporeal membrane oxygenation for hemodynamic support. The coronary angiography showed diffuse occlusive coronary artery vasospasm, ameliorated after intra-coronary administration of nitroglycerin. The following postoperative evolution was marked by cardiogenic shock and multiple organ dysfunction syndrome. Subsequent echocardiographic findings showed an increase in left ventricular function with an EF of 40%, and extracorporeal membrane oxygenation (ECMO) support was weaned after seven days. However, after a few hours, the patient progressively deteriorated, with cardiac arrest and no response to resuscitation maneuvers. Hemodynamic instability following the surgical procedure in a patient with previous PCI associated with an autoimmune disease and diabetes mellitus should raise the suspicion of a coronary artery vasospasm.

Beta blockers versus calcium channel blockers for provocation of vasospastic angina after drug-eluting stent implantation: a multicentre prospective randomised trial

Background

Drug-eluting stent-induced vasospastic angina (DES-VSA) has emerged as a novel complication in the modern era of percutaneous coronary intervention (PCI). Although beta blockers (BBs) are generally recommended for coronary heart disease, they may promote incidence of DES-VSA. This study aimed to compare the effects of calcium channel blockers (CCBs) perceived to be protective against DES-VSA and BBs on subsequent coronary events after second-generation drug-eluting stent implantation.

Methods

In this multicentre prospective, randomised study, 52 patients with coronary artery disease who underwent PCI for a single-vessel lesion with everolimus-eluting stent placement were randomised into post-stenting BB (N=26) and CCB (N=26) groups and followed for 24 months to detect any major cardiovascular events (MACE). A positive result on acetylcholine provocation testing during diagnostic coronary angiography (CAG) at 9 months was the primary endpoint for equivalence. MACE included all-cause death, non-fatal myocardial infarction, unstable angina, cerebrovascular disease or coronary revascularisation for stable coronary artery disease after index PCI.

Results

At 9 months, 42 patients (80.8%) underwent diagnostic coronary angiography and acetylcholine provocation testing. Among them, seven patients in each group were diagnosed with definite vasospasm (intention-to-treat analysis 26.9% vs 26.9%, risk difference 0 (−0.241, 0.241)). Meanwhile, the secondary endpoint, 24-month MACE, was higher in the CCB group (19.2%) than in the BB group (3.8%) (p=0.01). In detail, coronary revascularisation for stable coronary artery disease was the predominant endpoint that contributed to the greater proportion of MACE in the CCB group (CCB (19.2%) vs BB (3.8%), p=0.03).

Conclusions

The incidence of acetylcholine-induced coronary artery spasms did not differ between patients receiving BBs or CCBs at 9 months after PCI. However, a higher incidence of 2-year MACE was observed in the CCB group, suggesting the importance of BB administration.

Trial registration number

This study was registered at the Japanese University Hospital Medical Information Network (UMIN) Clinical Trial Registry (The Prospective Randomized Trial for Optimizing Medical Therapy After Stenting: Calcium-Beta Trial; UMIN000008321, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000009536).

Development of elastic artificial vessels with a digital pulse flow system to investigate the risk of restenosis and vasospasm

The postoperative risk of stenosis is a complex issue, with risk factors including the status of human umbilical vein endothelial cells, the shear stress of dynamic blood flow, and blood physiology. Current research would benefit from in vitro models that can mimic the microenvironment of living vessels, to study the response of endothelial cells to stent placement. In this study, we constructed a digital pulse flow system based on a group of programmable solenoid valves, to mimic dynamic blood flows in the left coronary artery. Elastic artificial vessels, with internally cultured endothelial cells, were used to simulate vessel function and physiology. Based on this novel platform, we systematically explored cell proliferation and function in artificial vessels implanted with bare metal stents or drug-eluting stents, using unstented vessels as controls, under static and pulse flow conditions. The results indicate that the natural shear stresses of dynamic blood flow actually benefit endothelial cell attachment and proliferation. And drug-eluting stents showed stronger inhibition of cell proliferation than bare metal stents, but had a more negative effect on the synthesis of nitric oxide synthase (NOS), suggesting that drug elution might reduce the postoperative risk of restenosis, while increasing the risk of vasospasm. The results suggest that stent evaluation should include both the risk of restenosis and the effect on endothelial cells. Our simulation establishes a realistic in vitro model for pathological studies of restenosis and vasospasm, shows potential for evaluation of new stent designs, and could help develop individualised therapies for patients with atherosclerosis.

Coronary Vasospasm After Burn Injury: First Described Case Series of a Lethal Lesion

Burn injuries generate multisystem physiological derangements. The authors present a case series of three patients developing acute coronary syndrome (ACS) stemming from coronary vasospasm (CVS) over a course of 5 months. This etiology of ACS is significant as it has previously not been described in burn patients and requires a different management algorithm than vaso-occlusive disease.All patients were admitted to a single accredited burn unit. Burn mechanisms were flash burn, chemical fire, and house fire. TBSA were 20%, 72%, and 31%, respectively. Ages were 67-, 41-, and 52-year-old men. All smoked tobacco, and one had diabetes and coronary artery disease. CVS presented with acute onset ST elevations, severe bradycardia, and cardiac arrest in all. Diagnosis was made via EKG and angiography. Treatment was undertaken with nitrates and calcium channel blockers. One of the patients died of refractory disease.The authors identified CVS in burn patients with an incidence of 2% of admissions and accounting for 17% of our burn mortality during this period. To date, there is no linkage between CVS and burns described in humans; however, there is a well-described animal model in rats. The risk factors for CVS are common among burn patients, particularly smoking and endothelial dysfunction. CVS may be a significant cause of ACS in burn patients, and it should be considered in the setting of ACS especially with a negative angiography. Knowledge of this disease state can change burn management to mitigate risk and accommodate specific cardiac treatments.