Niket Patel

Royal Free London NHS Foundation Trust | Royal Free · Cardiology Services

Objectives This study sought to evaluate in-hospital outcomes and 3-year mortality of patients presenting with unprotected left main stem occlusion (ULMSO) treated with primary percutaneous coronary intervention (PPCI). Background Limited data exists about management and outcome following presentation with ULMSO. Methods From January 1, 2007 to D...

Aims: Primary percutaneous coronary intervention (PPCI) is the optimal treatment for patients presenting with ST-elevation myocardial infarction (STEMI). An elevated index of microcirculatory resistance (IMR) reflects microvascular function and when measured after PPCI, it can predict an adverse clinical outcome. We measured coronary microvascular...

OBJECTIVES The aim of this study was to define which measure of microvascular best predicts the extent of left ventricular (LV) infarction. BACKGROUND Microvascular injury after ST-segment elevation myocardial infarction (STEMI) is an important determinant of outcome. Several invasive measures of the microcirculation at primary percutaneous corona...

Objectives: This study sought to assess the performance of cardiovascular magnetic resonance (CMR) myocardial perfusion mapping against invasive coronary physiology reference standards for detecting coronary artery disease (CAD, defined by fractional flow reserve [FFR] ≤0.80), microvascular dysfunction (MVD) (defined by index of microcirculatory r...

Aims Transcatheter aortic valve implantation (TAVI) is an alternative to surgical aortic valve replacement for patients with aortic valve stenosis. The choice between TAVI, surgery, or a conservative approach should be based upon multiple factors including clinical considerations, technical feasibility, and informed patient preference. In this cont...

Aims Cardiac involvement is the main driver of clinical outcomes in systemic amyloidosis and preliminary studies support the hypothesis that myocardial ischaemia contributes to cellular damage. The aims of this study were to assess the presence and mechanisms of myocardial ischaemia using cardiovascular magnetic resonance (CMR) with multiparametric...

Importance In the Revascularization for Ischemic Ventricular Dysfunction (REVIVED-BCIS2) trial, percutaneous coronary intervention (PCI) did not improve outcomes for patients with ischemic left ventricular dysfunction. Whether myocardial viability testing had prognostic utility for these patients or identified a subpopulation who may benefit from P...

Introduction Shared decision making (SDM) is a collaborative process empowering patients and healthcare professionals to engage in discussion around treatment goals and options (National Institute of Health and Care Excellence (NICE), 2023). This framework has long been promoted by NICE, but with limited implementation in practice. Methods We have...

Background No data currently exist comparing the contemporary iterations of balloon‐expandable (BE) Edwards SAPIEN 3/Ultra and the self‐expanding (SE) Medtronic Evolut PRO/R34 valves. The aim of the study was the comparison of these transcatheter heart valves with emphasis on patients with small aortic annulus. Methods and Results In this retrospe...

Background/Aims Most transcatheter aortic valve implantation procedures are now performed under conscious sedation, rather than general anaesthetic. This study evaluated nurse-led conscious sedation, compared with anaesthetist-led sedation, to determine the feasibility of the former. Methods Consecutive patients undergoing transcatheter aortic val...

Background Aortic Stenosis is the commonest single cardiac valve lesion and Transcatheter Aortic Valve Implantation (TAVI) is now the dominant treatment modality for intervention. The great majority of TAVI procedures are performed under sedation rather than general anaesthetic (GA) however the need for anaesthetist with operating department practi...

Objectives The aim of this study was to compare Doppler flow velocity and thermodilution-derived indexes and to determine the optimal thermodilution-based diagnostic thresholds for coronary flow reserve (CFR). Background The majority of clinical data and diagnostic thresholds for flow-based indexes are derived from Doppler measurements, and corres...

Background: Troponin elevation is common in hospitalized COVID-19 patients, but underlying aetiologies are ill-defined. We used multi-parametric cardiovascular magnetic resonance (CMR) to assess myocardial injury in recovered COVID-19 patients. Methods and results: One hundred and forty-eight patients (64 ± 12 years, 70% male) with severe COVID-...

Introduction: Cardiac involvement determines outcome in systemic amyloidosis, but the relationship between amyloid deposits and outcomes is poorly understood. Many clinical observations are not explained by the simple concept of physical, mechanical replacement of the interstitium by amyloid material. Hypothesis: Preliminary studies in patients wit...

Aims Assessment of hyperaemia during adenosine stress cardiovascular magnetic resonance (CMR) remains a clinical challenge with lack of a gold-standard non-invasive clinical marker to confirm hyperaemic response. This study aimed to validate maximum stress myocardial blood flow (SMBF) measured using quantitative perfusion mapping for assessment of...

OBJECTIVES: The authors sought to compare the diagnostic accuracy of quantitative perfusion maps to visual assessment (VA) of first-pass perfusion images for the detection of multivessel coronary artery disease (MVCAD). BACKGROUND: VA of first-pass stress perfusion cardiac magnetic resonance (CMR) may underestimate ischemia in MVCAD. Pixelwise perf...

Background: Coronary artery perforation during coronary intervention has high morbidity and mortality. This case describes the collaboration between interventional cardiologists and Interventional radiologists to successfully deploy a peripheral arterial stent graft in a coronary artery that demonstrated persistent extravasation after coronary spe...

Background Cardiac involvement is the main driver of outcome in systemic amyloidosis, but the relationship between amyloid deposits and outcomes is not well understood. The simple explanation of physical, mechanical replacement of the interstitium by amyloid seems insufficient. Preliminary studies support the hypothesis that myocardial ischaemia co...

Introduction NHS England announced a new nurse angiographer role with the purpose of reducing hospital waiting lists for elective angiography. Methods Development of a standardised operating procedure for training in Radial Arterial Access (RAA), guidance on how to minimise the risk and recognise complications and post procedural limb management....

Background Cardiac involvement is the main driver of outcome in systemic amyloidosis, but the relationship between amyloid deposits and outcomes is not well understood. The simple explanation of physical, mechanical replacement of the interstitium by amyloid seems insufficient. Preliminary studies support the hypothesis that myocardial ischaemia co...

Background Assessment of hyperaemia during adenosine stress CMR remains a clinical challenge with lack of a gold standard marker of adequate stress. Multiple parameters including the splenic switch off (SSO) sign, heart rate response (HRR) and blood pressure response (BPR) are used in clinical practice. Perfusion mapping provides a pixelwise repres...

Background: Coronary sinus (CS) blood sampling is important for measuring metabolites and biomarkers in cardiovascular research, but can be technically challenging. Here we demonstrate the use of the antecubital fossa for CS blood sampling as an alternative to femoral access, and a simple technique of paired venous and CS blood gas analysis for con...

Table S1. Guideline‐Recommended Risk Scores for ST‐Segment–Elevation Myocardial Infarction Figure S1. Scatter plot of indicates index of microcirculatory resistance (IMR) (A) and coronary flow reserve (CFR) (B) and mosaic plot of PAMI‐II (Primary Angioplasty in Myocardial Infarction II) (C) and Zwolle score (D) against major cardiac complications...

Background Early risk stratification after primary percutaneous coronary intervention (PPCI) for ST‐segment–elevation myocardial infarction is currently challenging. Identification of a low‐risk group may improve triage of patients to alternative clinical pathways and support early hospital discharge. Our aim was to assess whether the index of micr...

Background More than half of the patients undergoing percutaneous coronary intervention (PCI) have multivessel disease. Whether complete revascularization impacts long‐term mortality or whether selected patients or those with specific coronary anatomy benefit from complete revascularization is unclear. Methods A total of 14,452 patients underwent...

Objectives Early detection of microvascular dysfunction after acute myocardial infarction (AMI) could identify patients at high risk of adverse clinical outcome, who may benefit from adjunctive treatment. Our objective was to compare invasively measured coronary flow reserve (CFR) and hyperaemic microvascular resistance (HMR) for their predictive p...

Revascularization of significant Left Main Stem (LMS) disease improves clinical outcomes. This can be achieved through either Coronary Artery Bypass Grafting or Percutaneous coronary intervention. Defining a significant stenosis of the LMS can be challenging and debatable, as most data have been derived using angiographic assessment alone, with a t...

Objectives: The index of microcirculatory resistance (IMR) provides a reproducible assessment of the status of coronary microvasculature in patients with ST-elevation myocardial infarction (STEMI). Frequency-domain optical coherence tomography (FD-OCT) enables detailed assessment of the morphology of coronary plaque.We sought to determine the infl...

OBJECTIVE: To assess whether a novel 'direct access pathway' (DAP) for the management of high-risk non-ST-elevation acute coronary syndromes (NSTEACS) is safe, results in 'shorter time to intervention and shorter admission times'. This pathway was developed locally to enable London Ambulance Service to rapidly transfer suspected high-risk NSTEACS f...

Aims To compare optical coherence tomography (OCT)-derived plaque characteristics of the culprit and non-culprit coronary arteries in patients with Non ST elevation myocardial infarction (NSTEMI) and stable angina pectoris (SA). Methods Assessment of clinical data, angiographic, and OCT imaging including the analysis of plaques was performed. Plaqu...

Early reperfusion represents the key strategy in ST elevation myocardial infarction. However, reperfusion may induce myocardial damage due to the reperfusion myocardial injury, compromising the full potential of reperfusion therapy and accounting for unfavourable results in high risk patients. Adenosine seems to attenuate ischemia reperfusion injur...

Low and oscillatory wall shear stress promotes endothelial dysfunction and vascular disease. The aim of the study was to investigate the impact of an external stent on hemodynamic flow parameters in saphenous vein grafts (SVGs) and their correlation with the development of intimal hyperplasia. We performed post hoc computational fluid dynamics anal...

To analyze the immediate and long-term outcomes of transradial (TR) percutaneous coronary intervention (PCI) to unprotected left main stem (ULMS) bifurcation and to assess the main aspects affecting access-site choice in this specific PCI setting. TR-PCI to the ULMS is feasible, but data specifically comparing TR and transfemoral (TF) approaches in...

External stents inhibit saphenous vein graft (SVG) intimal hyperplasia in animal studies. We investigated whether external stenting inhibits SVG diffuse intimal hyperplasia 1 year after coronary artery bypass graft surgery. Thirty patients with multivessel disease undergoing coronary artery bypass graft surgery were enrolled. In addition to an inte...

A unifying definition of what constitutes high-risk percutaneous coronary intervention remains elusive. This reflects the existence of several recognized patient, anatomic, and procedural characteristics that, when combined, can contribute to elevating risk. The relative inability to withstand the adverse hemodynamic sequelae of dysrhythmia, transi...

Diabetic patients are prone to diffuse and accelerated atherosclerosis, which increases the likelihood of requiring myocardial revascularization. Diabetes mellitus is a strong risk factor for restenosis following coronary stenting, with greater need for repeat revascularization and inferior clinical outcomes. Despite the recent advances in drug-elu...

Introduction Limited data exists about management and outcome following presentation with unprotected left mainstem occlusion (ULMSO). To evaluate in-hospital outcomes and one-year mortality of patients presenting with ULMSO treated with primary percutaneous coronary intervention (PPCI). Methods 400,985 PCI cases were recorded in the British Cardio...

Randomized trials comparing multi-vessel percutaneous coronary intervention to coronary artery bypass grafting (CABG) have demonstrated the long-term superiority of CABG in diabetic patients. Benefits include improved survival, fewer recurrent myocardial infarctions and a lower risk of the need for repeat intervention. The focus of this review arti...

Aims: This study retrospectively compares the in-hospital outcomes for patients undergoing high-speed rotational atherectomy (HSRA) facilitated percutaneous coronary intervention (PCI) using either the radial or the femoral artery approach. From September 2008 to February 2013, 135 consecutive patients (75 femoral, 60 radial) underwent HSRA in our...

New intra-operative mitral regurgitation is an unusual complication of tricuspid annuloplasty and maybe ischemic in etiology as a consequence of right coronary artery distortion. We report the case of a woman in whom this was treated by mitral valve annuloplasty with ensuing hemodynamic instability and ventricular arrhythmia secondary to a new left...

A 66-year-old man with previous stenting to the left anterior descending coronary artery and the right coronary artery performed from the femoral approach presented with chest pain. Elective coronary angiography was performed from the right radial artery. Accessing the ascending aorta required

Conventional drug eluting stents allow predictable long-term relief from coronary obstruction in most cases. However, rigid permanent metallic stents alter flow dynamics, abolish vascular reactivity, limit the potential for maximal vasodilation and promote ongoing inflammation and abnormalities of endothelial function. It is hypothesised that they...

The detachment of atherothrombotic material from the atherosclerotic coronary plaque and downstream embolisation is an underrecognized phenomenon and it causes different degrees of impairment of the coronary microcirculation. During treatment of obstructive atherosclerotic plaque by percutaneous coronary intervention (PCI) distal embolisation (DE)...

Coronary artery bypass graft (CABG) surgery may induce myocardial stunning and thereby affect cardiac function. We aimed to assess whether myocardial function is affected by CABG in patients with preserved preoperative systolic function. Myocardial tissue peak velocities were recorded at the lateral and septal angle of the mitral annulus as well as...