Left main stem stenosis angioplasty with intravascular ultrasound optimisation criteria guidance using a new generation everolimus drug-eluting stent.

INTRODUCTION: Intravascular ultrasound (IVUS) is recommended in the use of left main stem (LMS) percutaneous coronary intervention (PCI). Since the LMS diameter is usually larger than other coronary arteries, a new generation everolimus drug-eluting stent (DES), Synergy Megatron DES (Boston Scientific) has better axial and radial strength allowing more post implant overexpansion and consequently better suited for LMS lesions. We performed a study to evaluate the clinical outcomes of PCI using 1) an improved IVUS protocol with optimisation targets and 2) the use of Megatron stents. MATERIALS AND METHODS: This was a study involving LMS PCI coronary lesions using the Synergy Megatron DES. An IVUS protocol using predefined optimisation targets to evaluate for stent malapposition, longitudinal stent deformation, optimal stent expansion >90% of reference lumen and appropriate distal landing zone was used in all cases. The primary end-point was procedural success, defined by successful stent implantation with <30% residual stenosis. The secondary end-point was in-hospital and 30-day major adverse cardiovascular event (MACE). RESULTS: Eight patients with significant LMS stenosis were successfully treated with the Megatron stent. The primary end-point was achieved in all patients. There were no cases of stent malapposition or longitudinal stent deformation, one case did not have optimal LMS stent expansion and one case did not have an appropriate distal landing zone. IVUS optimisation criteria were met in 6 (75%) cases. There were no complications of coronary dissection, slow or no reflow, stent thrombosis or vessel perforation. None of the patients suffered in-hospital or 30-day MACE. The average LMS MLD at baseline was 2.1 ± 0.1mm and the post-PCI LMS MLD was 4.0 ± 0.5mm, with a significant acute luminal gain of 1.9 ± 0.7mm (p<0.01). A post-PCI MSA of 17 ± 3.9 mm2 was numerically superior compared to those documented in other LMS PCI trials. CONCLUSION: This study demonstrates low rates of shortterm major adverse cardiovascular events among patients with LMS PCI using the Megatron stents. It highlights the usefulness of IVUS-guided optimisation in LMS PCI. With the use of intravascular imaging, the new generation stent technology can improve the treatment of large proximal vessels and PCI of LMS lesions.

Intravascular imaging-guided treatment of severe coronary artery calcification with orbital atherectomy: A prospective single-centre registry.

INTRODUCTION: Coronary artery calcification can lead to suboptimal results when performing coronary angioplasty with conventional techniques. The presence of severe coronary artery calcium increases the complications of percutaneous coronary intervention as it may impede stent delivery and optimal stent expansion. The purpose of this study was to determine the procedural success and safety of orbital atherectomy (OA) in calcified lesions. MATERIALS AND METHODS: This was a prospective single-centre study regarding the utility of OA in the treatment of calcified coronaries. Intravascular ultrasound (IVUS) or optical coherence tomography (OCT) was used in all cases to characterise the severity of calcium pre-procedure, guide vessel sizing and assess procedural success. The primary endpoint was procedural success, defined by successful stent implantation following OA treatment. The secondary endpoint was in-hospital and 30-day major adverse cardiovascular event (MACE). RESULTS: Ten patients with severely calcified lesions were successfully treated with OA. The primary endpoint was achieved in all patients. All of the lesions were severely calcified with concentric calcium. None of the patients suffered in-hospital or 30-day MACE. The average minimal luminal diameter at baseline was 1.7 ± 0.3 mm and the post- PCI luminal diameter was 3.0 ± 0.3 mm, with a significant luminal gain of 1.3 ± 0.3 mm (p < 0.01). Slow flow during procedure occurred in 2 (20%) cases and dissection occurred in 1 (10%) case during procedure. These were successfully treated with stent delivery to achieve TIMI III flow. There were no cases of stent thrombosis or vessel perforation. CONCLUSION: Our experience demonstrates the feasibility and safety of OA in the management of calcified coronary stenosis. Intravascular imaging is an important adjunct to the use of OA to assess the severity of calcified coronary lesions, success of OA treatment and to aid sizing of the vessel for stent implantation. OA is an effective treatment approach to disrupt coronary calcification, facilitating stent implantation with optimal results. It is a safe procedure with good success rate and low rate of complications.

Treatment of severe coronary artery calcification with intravascular lithotripsy: Initial experience of a prospective single centre registry.

INTRODUCTION: Coronary artery calcification can lead to suboptimal results when performing coronary angioplasty with conventional techniques. Shockwave intravascular lithotripsy (IVL) has recently been introduced as a new modality to treat heavily calcified coronary arteries. The purpose of this study was to determine the procedural success and safety of IVL in calcified lesions. MATERIALS AND METHODS: This was a prospective single-centre study regarding the utility of IVL in treatment of calcified coronary arteries. Intravascular ultrasound (IVUS) was used in all cases to characterise the lesions pre procedure and to assess procedural success post procedure. The primary end point was procedural success, defined by IVL treatment and successful stent implantation. The secondary end point was in-hospital and 30-day major adverse cardiovascular event (MACE). RESULTS: Five patients with severely calcified lesions were successfully treated with IVL. The primary end point was achieved in all patients. All of the lesions were severely calcified with concentric calcium. Multiple calcium fractures were identified on IVUS after IVL in all cases. None of the patients suffered in-hospital or 30-day MACE. The average diameter stenosis at baseline was 1.8±0.4mm and the post PCI diameter stenosis was 2.9±0.1mm, with significant acute luminal gain of 1.2±0.3mm (p<0.01). There were no complications of coronary dissection, slow or no reflow, stent thrombosis, or vessel perforation. CONCLUSION: Our initial experience demonstrates the feasibility and safety of IVL in the management of calcified coronary stenosis. The shockwave IVL is an effective treatment approach to disrupt coronary calcification, facilitating stent implantation with optimal results. It is a safe procedure with a good success rate and low rate of complications.

A comparison of dabigatran and warfarin for stroke prevention in elderly Asian population with nonvalvular atrial fibrillation: An audit of current practice in Malaysia.

INTRODUCTION: Atrial fibrillation (AF) is the most common cardiac arrhythmia with significant morbidity and mortality in relation to thromboembolic stroke. Our study aimed to evaluate the safety and efficacy of dabigatran in stroke prevention in elderly patient with nonvalvular AF with regard to the risk of ischemic stroke and intracranial haemorrhage (ICH) in real-world setting. METHODS: A retrospective cohort study of 200 patients on dabigatran and warfarin from January 2009 till September 2016 was carried out. Data were collected for 100 patients on dabigatran and 100 patients on warfarin. RESULTS: The mean follow-up period was 340.7±322.3 days for dabigatran group and 410.5±321.2 days for warfarin group. The mean time in therapeutic range (TTR) was 52±18.7%. The mean CHA2DS2 -VASc score for dabigatran group was 4.4±1.1 while 5.0±1.5 for warfarin group. None in dabigatran group experienced ischemic stroke compared to one patient in warfarin group (p=0.316). There was one patient in dabigatran group suffered from ICH compared to none in warfarin group (p=0.316). Four patients in warfarin group experienced minor bleeding, while none from dabigatran group (p=0.043). CONCLUSION: Overall bleeding events were significantly lower in dabigatran group compared to warfarin group. In the presence of suboptimal TTR rates and inconveniences with warfarin therapy, non-vitamin-K antagonist oral anticoagulants (NOAC) are the preferred agents for stroke prevention in elderly Asian patients for nonvalvular AF.

Stress fracture of the ulna associated with bisphosphonate therapy and use of walking aid.

We report a case of a stress fracture of the ulna secondary to long-term bisphosphonate therapy and walking cane. Physicians need to have a high index of suspicion of stress fractures occurring in patients complaining of chronic upper limb pain if they are on bisphosphonate therapy and are using walking aids. Stress fractures of the upper extremities are rare and are usually associated with athletes; however, a few recent case reports have shown an association between stress fractures of the upper extremities and the use of walking aids. The association between increased incidence of upper extremity stress fractures and the use of both bisphosphonates and walking aids in patients has not been well studied, with only one previously reported case. Here, we report a case of a complete stress fracture of the ulna in a 77-year-old female, premorbidly ambulant with walking cane, on long-term bisphosphonates without any pre-existing medical conditions which could result in secondary causes of bone loss. Investigations did not reveal any causes of pathological fracture. This fracture is attributed to the use of long-term bisphosphonate therapy in conjunction with the use of a walking cane. This case highlights the importance of entertaining the possibility of such fractures occurring in any patient who is on bisphosphonate therapy presenting with stress fractures of the upper extremity.