Brief Summary
This inaugural lecture by Professor Jim Nolan discusses advancements in heart disease treatment, focusing on heart rate variability analysis for risk stratification in heart failure patients and the transition from femoral to radial access for coronary angioplasty. It highlights the benefits of radial access in reducing complications and mortality, supported by extensive data and research.
- Heart rate variability analysis can effectively risk stratify heart failure patients.
- Radial access for angioplasty significantly reduces complications and mortality compared to femoral access.
- Education and training are crucial for adopting new medical practices.
Introduction
Trevor McMillan, the Vice Chancellor of Keel University, introduces Professor Jim Nolan's inaugural lecture, emphasizing the importance of such lectures in highlighting the university's world-class research and collaborative relationships, particularly with the NHS. He acknowledges the difficulty in summarizing Jim Nolan's extensive CV and opts to provide a brief overview before handing over to Professor Nolan.
Jim Nolan's Background
Jim Nolan qualified from Leeds in 1983 and trained in cardiology at prestigious institutions, including the Royal Free in London, the Royal Infirmary in Edinburgh, and in Amsterdam. During his time in Amsterdam, he received training in novel techniques for safer coronary intervention procedures. He has played a significant role in research, education, and training related to these techniques, leading to the evolution of UK practice in coronary intervention. He also conducted research on chronic heart failure, earning his MD from Leeds University in 1996. Despite being a full-time NHS clinician, Jim has an impressive research record, focusing on heart failure and trans-radial access for coronary intervention, establishing an internationally recognized cardiac research program.
Conflict of Interest and Research Career Beginnings
Professor Nolan jokingly declares his "conflict of interest" as a Stoke City supporter. He then reflects on the start of his research career, recounting an early experience as a cardiology registrar at the Royal Free where he implanted a pacemaker into a dog with complete heart block, marking an unconventional beginning to his work in clinical cardiology.
Heart Rate Variability and Cardiovascular Health
Professor Nolan explains that cardiovascular disease is a major cause of death, often resulting from ischemic heart disease and its complications. He discusses his research in Edinburgh, which focused on heart rate behavior as an indicator of cardiovascular health. He describes how heart rate constantly varies due to a complex neurological system controlled by the cardiovascular control center in the brain, and how measuring this variability can provide insights into the autonomic nervous system's function and the health of the cardiovascular system.
Studies on Heart Rate Variability
Professor Nolan details a study conducted in Edinburgh where a method was developed to measure heart rate variability over a 24-hour period. The technique proved reproducible, showing consistent results when measurements were taken on different days. Subsequent studies on patients with severe coronary artery disease but without prior heart attacks showed that most had heart rate variability within the normal range. In contrast, a study on patients with chronic heart failure revealed that 60-70% had reduced heart rate variability, indicating the severity of their condition.
Linking Heart Rate Variability to Prognosis in Heart Failure
Professor Nolan discusses a study conducted after leaving Edinburgh, which aimed to link heart rate variability to outcomes and prognosis in heart failure. Despite initial lack of support, he and his colleagues recruited around 500 patients with chronic heart failure, measured their heart rate variability, and followed them up for a couple of years. The results showed that patients with very abnormal heart rate variability had a significantly lower survival rate compared to those with preserved heart rate variability.
Therapeutic Intervention and Further Research
The research team demonstrated that heart rate variability could be improved by putting patients on an ACE inhibitor called captopril, indicating a potential therapeutic tool. The series of heart failure studies concluded that autonomic control of heart rate is impaired in heart failure, which can be reliably investigated through heart rate variability analysis. The degree of impairment is related to the severity of the condition, can be modified by drug therapy, and is strongly predictive of survival, guiding treatment decisions. Subsequent research included analyzing different ways people die, various prognostic factors, and different heart rate variability analytical techniques, including collaboration with NASA to use supercomputers for complex analysis.
Treatment of Coronary Disease Through Stent Implantation
Professor Nolan transitions to discussing the treatment of coronary disease through stent implantation, illustrating the process with an angiogram of a patient. He explains how a catheter is inserted into the vascular system to position a balloon in the narrowed section of the artery. Inflating the balloon widens the artery, and a metal coil (stent) is left behind to maintain the opening.
Challenges with Femoral Artery Access
Professor Nolan discusses the traditional method of accessing the heart through the femoral artery in the groin and the complications associated with it. Puncturing the femoral artery can lead to blockage, damage, bleeding, and hematoma formation, with complication rates ranging from 10 to 20%. These complications significantly increase the risk of mortality.
Brachial Artery Access as an Alternative
Professor Nolan explores using the brachial artery in the arm as an alternative access point. A study showed that using the brachial artery reduced access site complications in anti-coagulated patients. However, this procedure is technically challenging due to the difficulty in distinguishing between the artery, vein, and nerve, and requires extensive experience to avoid complications.
Radial Artery Access: A Safer Approach
Professor Nolan discusses the transition to radial artery access, influenced by data from Amsterdam showing significantly lower complication rates. He spent six months in Amsterdam learning the technique. The radial artery is safer due to its superficial location, ease of compression, and the hand's dual blood supply, which minimizes the risk of ischemic complications.
Initial Experience with Radial Access and Overcoming Opposition
Professor Nolan shares data from the first thousand radial cases at North staffs, showing a complication rate of only 0.3%, a significant improvement compared to femoral access. Radial access also allowed for quicker patient mobilization. Despite these benefits, there was initial opposition from colleagues who questioned the results and claimed the procedures were too difficult.
Addressing Concerns and Demonstrating Benefits in High-Risk Patients
Professor Nolan addresses the criticisms by presenting data on high-risk patients, including those undergoing rescue angioplasty and patients with mechanical heart valves, demonstrating the safety and efficacy of radial access in these populations. He also highlights a study showing improved survival rates in cardiogenic shock patients who underwent radial angioplasty compared to femoral angioplasty.
Managing Radial Spasm and Anatomical Variations
Professor Nolan discusses the challenges of radial spasm and anatomical variations in the arm. Studies showed that administering GTN could increase radial artery diameter, reducing spasm. Additionally, arm angiograms revealed anatomical variations in 14% of patients, which could impact the success of radial procedures. Identifying these variations allows operators to choose the best approach, such as using an alternative access site.
Addressing Radiation Exposure Concerns
Professor Nolan addresses concerns about increased radiation exposure with radial procedures, debunking the myth with well-controlled studies. These studies showed no significant difference in radiation exposure between radial and femoral access when accounting for operator expertise and patient characteristics. He also discusses various methods to reduce radiation exposure, such as using shields and proper techniques.
Stroke Risk and the Benefits of Radial Access
Professor Nolan addresses the misconception that radial access leads to a higher risk of stroke. He explains that while radial access involves traversing vessels supplying blood to the brain, femoral access involves navigating through the aorta, which has a higher incidence of atheroma. Data from the British Cardiovascular Intervention Society database, encompassing nearly 350,000 angioplasty procedures, showed no increased risk of stroke with radial access. Randomized trials further confirmed these findings.
Mortality Reduction and Long-Term Benefits
Professor Nolan presents evidence from randomized trials showing a 50% reduction in mortality with radial access for primary angioplasty. Analysis of nearly 50,000 patients from the BCIS database confirmed these findings, demonstrating a 30% mortality reduction with radial access. These benefits extend beyond primary angioplasty, with a study of nearly half a million patients showing reduced blood transfusions, vascular complications, and mortality with radial access across various patient groups.
Challenging Femoral Closure Devices and Maintaining Femoral Skills
Professor Nolan addresses the argument that femoral closure devices negate the benefits of radial access, presenting data showing that radial access still results in better outcomes compared to femoral access with closure devices. He also refutes the idea that radial operators lose their ability to perform femoral procedures, demonstrating that radial operators achieve similar or better outcomes in femoral procedures compared to dedicated femoral operators.
Education, Training, and National Impact
Professor Nolan emphasizes the importance of education and training in promoting the adoption of radial access. He discusses the various courses and educational initiatives undertaken to train other doctors in radial procedures. These efforts have significantly impacted national practice, with radial access now accounting for a substantial majority of angioplasty procedures in the UK.
Potential Complications and Concluding Remarks
Professor Nolan acknowledges potential complications associated with radial access, such as pseudoaneurysms, AV fistulas, and perforations, but notes that these are generally minor and manageable. He concludes by reiterating the benefits of radial access and the importance of challenging the status quo to improve clinical practice. He also thanks the staff, colleagues, and family for their support.
