Landmarks in the development of coronary artery bypass surgery

F. Mason Sones Jr.: The Serendipitous Discovery of Coronary Angiography and Its Lasting Impact on Cardiology

F. Mason Sones Jr. (1918-1985) was a pioneering cardiologist whose groundbreaking work revolutionized the field of cardiology. His accidental discovery of coronary angiography in 1958 at the Cleveland Clinic provided physicians with the first clear visualization of coronary arteries in living patients, paving the way for the development of coronary artery bypass surgery and interventional cardiology. This review article explores F. Mason Sones Jr.'s life and career, and his lasting impact on the field of cardiology. Born in Noxapater, MS, in 1918, F. Mason Sones Jr. attended Western Maryland College (Westminster, MD) and the University of Maryland School of Medicine (Baltimore, MD) before completing his internship and residency at the University Hospital (Baltimore, MD) and Henry Ford Hospital (Detroit, MI), respectively. After serving in the U.S. Army Air Corps during World War II, F. Mason Sones Jr. joined the Cleveland Clinic (Cleveland, OH), in 1950, as the head of pediatric cardiology, where he combined his expertise in cardiac catheterization with his interest in congenital heart disease. F. Mason Sones Jr.'s serendipitous discovery of coronary angiography occurred during a routine cardiac catheterization procedure when he inadvertently injected contrast dye directly into the right coronary artery. Realizing that smaller amounts of dye could safely opacify the coronary arteries, F. Mason Sones Jr. refined and standardized the technique of selective coronary angiography, collaborating with engineers to improve X-ray imaging and establishing protocols that remain the standard of care today. F. Mason Sones Jr.'s work provided the foundation for the development of coronary artery bypass surgery by Dr. René Favaloro and the birth of interventional cardiology, as pioneered by Dr. Andreas Gruentzig. As the director of cardiovascular disease at the Cleveland Clinic (1966-1975), F. Mason Sones Jr. mentored and inspired a generation of cardiologists, cementing his legacy as a visionary leader in the field. Throughout his career, F. Mason Sones Jr. received numerous awards and honors, including the American Medical Association's Scientific Achievement Award and the Gairdner Foundation International Award. He co-founded and served as the first president of the Society for Cardiac Angiography (now SCAI), an organization dedicated to advancing the field of interventional cardiology. This review article pays tribute to F. Mason Sones Jr.'s enduring contributions to the field of cardiology, highlighting his role as a pioneer, innovator, and mentor. His legacy continues to inspire and guide generations of cardiologists in their pursuit of improving patient care and pushing the boundaries of cardiovascular medicine.

Epidemiology of Coronary Artery Disease

Although the mortality of coronary artery disease (CAD) has declined over recent decades, CAD remains the leading cause of death in the United States (US) and presents a significant economic burden. Epidemiologic studies have identified numerous risk factors for CAD. Some risk factors-including smoking, hypertension, dyslipidemia, and physical inactivity-are decreasing within the US population while Others, including advanced age, diabetes, and obesity are increasing. The most significant historic advances in CAD therapy were the development of coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), and lipid-lowering medications. Contemporary management of CAD includes primary and secondary prevention via medical management and revascularization when appropriate based on best available evidence. Despite the increasing prevalence of CAD nationwide, there has been a steady decline in the number of CABGs and PCIs performed in the US for the past decade. Patients with CABG are becoming older and with more comorbid conditions, although mortality associated with CABG has remained steady.

ISCHEMIA trial: How to apply the results to clinical practice

During the last years two questions have been continuously asked in chronic coronary syndromes: (1) Do revascularization procedures (coronary artery bypass grafting or percutaneous coronary intervention) really improve symptoms of angina? and (2) Do these techniques improve outcomes, i.e. do they prevent new myocardial infarction events and cardiovascular death? Therefore, there was a need for a large definitive trial. This study was the ISCHEMIA trial, a large, multicentric trial sponsored by the National Heart, Lung, and Blood Institute. The main trial compared coronary revascularization and optimal medical treatment (OMT) vs OMT alone in 5179 patients enrolled after a stress test. During a median 3.2-year follow-up, 318 primary outcome events occurred; the adjusted hazard ratio for the invasive strategy as compared with the conservative strategy was 0.93 (95% confidence interval 0.80-1.08, P = 0.34). The ISCHEMIA trial deeply disrupted many of our prior attitudes regarding management strategies for patients with stable coronary artery disease. The findings underscore the benefits of disease-modifying OMT for stable coronary artery disease patients. The main purposes of ischemia assessment before this trial were: Diagnostic purposes, assessment of outcome, and adding to decision-making processes. Obviously, this changed after the trial results. The results of ISCHEMIA might challenge the current diagnostic approach for stable angina patients recommended in the last European Society of Cardiology guidelines on chronic coronary disease that were based on studies published before the ISCHEMIA trial. In this editorial we propose our approach based on the ISCHEMIA study and the pretest probability for a positive test in patients with chronic coronary syndromes.

Who is who in cardiovascular research? What a review of Nobel Prize nominations reveals about scientific trends

Background

Since 1901, at least 15 scholars who contributed to cardiovascular research have received a Nobel prize in physiology or medicine.

Methods

Using the Nobel nomination database (nobelprize.org), which contains 5950 nominations in the accessible period from 1901 to 1953 in physiology or medicine, we listed all international nominees who contributed to cardiovascular research. We subsequently collected nomination letters and jury reports of the prime candidates from the archive of the Nobel Committee in Sweden to identify shortlisted candidates.

Results

The five most frequently nominated researchers with cardiovascular connections from 1901 to 1953 were, in descending order, the surgeon René Leriche (1879–1955) (FR) with a total of 79 nominations, the physiologist and 1924 Nobel laureate Willem Einthoven (1860–1927) (NL) (31 nominations), the surgeon Alfred Blalock (1899–1964) (US) (29 nominations), the pharmacologist and 1936 Nobel laureate Otto Loewi (1873–1961) (DE, AT, US) (27 nominations) and the paediatric cardiologist Helen Taussig (1898–1986) (US) (24 nominations). The research of these scholars merely hints at the width of topics brought up by nominators ranging from the physiological and pathological basics to the diagnosis and (surgical) interventions of diseases such as heart malformation or hypertension.

Conclusion

We argue that an analysis of Nobel Prize nominations can reconstruct important scientific trends within cardiovascular research during the first half of the twentieth century.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01813-2.

Living history of medicine: vascular scaffolding, from dream to reality

Following the launch of balloon angioplasty in 1977, its deficiencies-abrupt occlusion requiring emergency bypass surgery in one in twenty attempts and recurrence in one in three cases-became soon apparent. The attempts to eliminate the element of chance from this otherwise highly attractive technique resulted in the concept of intra-vascular scaffolding. Following the inception of self-expanding mesh stents made from stainless steel and extensive bench testing and animal experiments, the first clinical data were obtained in Switzerland almost 30 years ago in 1986 with promising, albeit not undisputed results. Technical improvements including potent platelet inhibitors have made the technique a cornerstone of catheter-treatment of vascular disease. This paper gives an account of the sometimes difficult beginnings of coronary and non-coronary stenting at the University of Lausanne in Switzerland.

TOUGH Syndrome: A Report of an Early Immediate Postoperative Cause of Aortocoronary Graft Occlusion

Aortocoronary artery bypass grafts are time tested to be effective definitive therapy of symptomatic coronary artery disease since their inception in the 1960s. Over the years, multiple factors have affected the long-term outcome and patency rates of vein grafts. These can be divided into acute, subacute, and delayed categories. The most common causes, respectively, are thrombosis, intimal hyperplasia, and accelerated atherosclerosis. Numerous studies have analyzed postoperative angiographic images to evaluate these phenomena, and medical therapies have been instituted to prevent occlusion of these grafts. Besides these pathologic mechanisms, a surgeon and the surgeon's team must be aware of potential early reversible causes of coronary occlusion that are most often mechanical in nature. Graft kinking and external compression are known adverse events that may require early intervention to correct the underlying cause of graft occlusion. Here we present a case of graft occlusion by what we refer to as TOUGH syndrome: Thoracostomy tube Occluding Underlying coronary Graft causing Harm.

Off-Pump Surgery: A Choice in Unstable Angina

The benefit and safety of off-pump coronary artery bypass surgery in patients with unstable angina was assessed retrospectively. From February 1996 to October 2001, 5,306 patients underwent multivessel off-pump coronary artery bypass, of whom 920 (17%) had unstable angina. In these 920 patients, ejection fractions ranged from 15% to 70%, 203 (22%) had an ejection fraction of 20%–35%, and 11 (1%) had an ejection fraction < 20%. Triple-vessel disease was present in 625 patients. Preoperative intraaortic balloon pump support was used in 28 patients. Operative approaches included mid sternotomy (86%), lower partial sternotomy (9%), and left anterior thoracotomy (2%). The number of grafts ranged from 1 to 5 with a mean of 2.43 ± 0.86, and 92.3% of patients received a left internal mammary artery graft. Twenty-two patients need intraoperative intraaortic balloon pumping. Ten patients (1%) suffered perioperative myocardial infarction. The mean hospital stay was 7.8 ± 4.3 days. Hospital mortality was 2/920 (0.22%). Intraaortic balloon pumping was helpful in these cases of unstable angina refractory to medical therapy. Off-pump coronary artery surgery was found to be safe and beneficial in these patients.

The history of arterial revascularization: from Kolesov to Tector and beyond

Coronary artery bypass grafting (CABG) is the one of the most effective revascularization strategies for patients with obstructive coronary artery disease. Total arterial revascularization using one or both internal thoracic and radial arteries has been shown to improve early outcomes and reduce long-term cardiovascular morbidity. Although CABG has evolved from an experimental procedure in the early 1900's to become one of the most commonly performed surgical procedures, there is still significant variation in grafting strategies amongst surgeons. We review the history and development of CABG with a particular emphasis on the early pioneers and the evolution of arterial grafting.

[Drug-eluting stents: implications for modern coronary revascularization]

Despite considerable data and years of experience in the field of coronary interventions and coronary surgery existing guidelines, which are still valid in the era of drug-eluting stents (DES), are often not followed. An increasing number of patients are treated with DES implantations against current recommendations. Due to antiplatelet therapy this impedes the planning and execution of additional invasive procedures that might be necessary after DES implantation and results in higher risks, if delaying treatment is not possible. As alternatives to stent implantation, coronary surgery nowadays offers a full range of individual treatment options which are highly effective and durable. They can be performed at low risk and do not interfere with subsequent invasive therapies. Patients suffering from relevant coronary artery disease and who are in need of additional invasive treatment should be considered for coronary surgery rather than stent implantation. If current guidelines are followed more closely, DES implantations and their accompanying drawbacks could be significantly reduced.

Non-invasive assessment of saphenous vein graft patency in asymptomatic patients

The development and progression of atherosclerotic disease in saphenous vein grafts (SVGs) following coronary artery bypass surgery (CABG) are often without symptoms. Four-slice CT is a non-invasive imaging technique reliable for assessing SVG patency. This study utilised CT to assess temporal progression of patency in asymptomatic patients. A four-slice CT scanner was used employing standard techniques. Analysis of the reconstructed images was performed offline by two experienced operators blinded to patient details. The primary aim was vein graft patency. 130 asymptomatic subjects were studied. The mean time from CABG was 7.3 years (range, 15 days to 21 years 9 months; standard deviation (SD), 4.4 years). 294 of the 305 SVGs were suitable for assessment of patency. The overall occlusion rate for assessable grafts was 23.5%. Occlusion rates for grafts <1 year old was 12.5% (2/16), 20.7% (42/203) for grafts 1-10 years old, and 33.3% (25/75) for grafts >10 years old. In conclusion, significant occlusion of SVGs occurs early after CABG in asymptomatic patients. Four-slice CT has the potential for the non-invasive assessment of individuals after surgery.

Saphenous Vein Grafts: to Use or Not to Use?

The choice of the graft conduit is crucial to the success of coronary artery bypass grafting (CABG) because the patency of a coronary conduit is closely associated with an uneventful postoperative course and better long-term patient survival. From the beginning of coronary bypass surgery venous conduits particularly the great saphenous vein (GSV) has been the most frequently used coronary conduit. However, over the last decade or so, coronary bypass graft surgery with arterial revascularization of all diseased coronaries has shown to be efficient because arterial grafts have better long-term patency, especially left internal mammary artery (LIMA), compared with venous grafts. Early vein graft failure coupled with occlusion is the most important limitation of saphenous vein grafts. Nevertheless, vein grafting is still an integral part of cardiac surgical practice. This review provides a summary of the patency rates, technical features and certain characteristics of the venous conduits. It also examines the current understanding and knowledge of venous histology, vein graft pathology and the associated endothelial and smooth muscle cell physiology and pharmacology. In addition, the existing and the emerging strategies to combat and control vein graft intimal hyperplasia and accelerated atherosclerosis are reviewed in detail.

Off-pump coronary surgery: how do the anesthetic considerations differ?

In recent years, there has been much interest in performing coronary artery bypass graft (CABG) surgery without the aid of cardiopulmonary bypass (CPB). Initial efforts focused on "minimally invasive" direct coronary artery bypass, wherein the left anterior descending artery is bypassed with an in situ left internal mammary artery graft through a small left anterior thoracotomy. A more widely adopted approach however, is off-pump CABG (OPCAB), in which CABG surgery is performed on one or more vessels through the usual median sternotomy approach without the aid of CPB. This article reviews the differences in the anesthetic considerations of OPCAB compared to conventional CABG using CPB.

Apoptosis and histopathologic changes in diffuse coronary atherosclerosis

The aims of the study were to investigate the histopathologic characteristics of atherosclerotic lesions and to evaluate the role of apoptosis or programmed cell death in diffuse coronary atherosclerosis. The study included 59 patients who underwent coronary artery bypass grafting coupled with coronary endarterectomy because of diffuse coronary atherosclerosis. Histopathologic analysis of endarterectomy sequesters showed atheroma with confluent extracellular lipid core-type IV lesions in 13 cases (22%); atheroma with lipid core and a cap of fibromuscular layers-type V lesions in 9 cases (15.3%); predominantly calcified fibrous tissue-type VII lesions in 13 cases (22%); and predominantly fibrous tissue-type VIII lesions in 24 cases (40.7%). TUNEL-positive cells were observed in 4 endarterectomy sequesters (6.8%) of subjects with diffuse coronary atherosclerosis. TUNEL-positive cells were demonstrated in the area of mononuclear infiltrates as well as in the vessel wall. The percentage of TUNEL-positive cells in mononuclear infiltrates was 0.5%. Intense mononuclear infiltrates in tunica intima were found in 50% of sequesters, and they consisted of macrophages (40%), T-lymphocytes (17%), and B-lymphocytes (14%). In the area of infiltrates the proportion of MIB-1-positive cells was 2.7%, which was higher than in the intima outside the area of infiltrates (0.5%). In conclusion, apoptosis, which is confined to mononuclear infiltrates, is most likely involved in the development of diffuse coronary atherosclerosis; however, the percentage of apoptotic cells was low (0.5%). A higher proportion of apoptotic cells in the area of infiltrates compared to the rest of the intima was associated with a higher proportion of MIB-1-positive cells. Atherosclerotic lesions in diffuse coronary atherosclerosis were advanced, with a predominance of type VII to VIII lesions.

Flow dynamics in internal thoracic artery grafts 10 years after coronary artery bypass grafting

BACKGROUND

Flow dynamics in internal thoracic artery grafts 10 years after surgery are not known.

METHODS

Doppler examination was performed in native internal thoracic arteries as a control (n = 8) and in internal thoracic artery grafts to the left anterior descending coronary artery 6 months postoperatively (group A, n = 25), at 5 years (group B, n = 14), and at 10 years (group C, n = 11).

RESULTS

Each graft group showed a diastolic to systolic peak velocity ratio of less than 1.0 at the proximal end, and more than 1.0 at the distal end, but the control group showed a ratio of less than 1.0 throughout the length of the artery. The diastolic peak velocity of the graft groups was significantly faster than that of the control group at the distal end (versus group A, p < 0.01; versus group B, p < 0.005; and versus group C, p < 0.05). The systolic peak velocity of the graft groups was significantly lower than that of the control at the proximal end (versus group A, p < 0.0001; versus group B, p < 0.005; and versus group C, p < 0.0005). There were no significant differences of flow velocities among the graft groups and graft diameter among the four groups.

CONCLUSIONS

Although the internal thoracic artery is systolic predominant, when native artery is used as graft, it changes its hemodynamics to diastolic predominance, especially at the distal end. Even after 10 years, graft flow dynamics are unchanged. This hemodynamic character may be one of the factors related to the superior long-term patency.

Management of dyslipidemia after coronary artery bypass grafting

The results of serial angiographic studies and intervention trials in patients after coronary artery bypass artery grafting have provided ample evidence that abnormalities of the plasma lipoprotein system are one of the most significant risk factors for a rapid atherosclerotic attrition of saphenous vein grafts. In addition to confirming the well recognized role and contribution of cholesterol-rich LDL or lipoprotein B particles to the progression of atherosclerotic lesions, intervention trials have also provided strong evidence for the atherogenic capacity of some intact and partly delipidized triglyceride-rich very low density lipoprotein and intermediate density lipoprotein (lipoprotein B complex) particles, and the protective effect of some (high density lipoprotein 3) but not all high density lipoprotein particles. Most importantly, those studies have emphasized the need for an early, aggressive treatment of dyslipoproteinemias with pharmacological agents as the most efficient therapeutic approach to delaying, if not preventing, the detrimental effect of atherosclerosis on saphenous vein grafts.

Vineberg revisited. Long-term survival more than two decades after direct surgical myocardial revascularization

A 65-year old patient was referred to our institution for a diagnostic catheterization. 23 years before, a direct surgical myocardial procedure using the Vineberg technique was performed. Currently, the angiogram shows patent left and right internal mammary arteries implanted directly into the myocardium and connecting with the native circulation through collaterals. As the native coronary artery tree shows very severe three vessel disease, it is hypothesized that the major contribution of myocardial perfusion comes from the implanted vessels. This is the first case to show a long-term success of the Vineberg operation, with persistence of myocardial perfusion through newly formed vasculature.

[The practical clinical guidelines of the Sociedad Española de Cardiología on coronary surgery]

Surgery in coronary disease, including myocardial revascularization and the surgery of mechanical complications of acute myocardial infarction, has shown to improve the symptoms, quality of life and/or prognosis in certain groups of patients. The expected benefit in each patient depend on many well-known factors among which the appropriateness of the indication for surgery is fundamental. The objective of these guidelines is to review current indications for cardiac surgery in patients with coronary heart disease through an evaluation of the degree of evidence of effectiveness in the light of current knowledge (systematic review of bibliography) and expert opinion gathered from various reports. Indications and the degree of recommendation for conventional coronary artery bypass grafting have been established for each of the most frequent anatomo-clinical situations defined by clinical symptoms (stable angina, unstable angina and acute myocardial infarction) as well as by left ventricular function and extend of coronary disease. Furthermore, the subgroups with the greatest surgical risk and stratification models are described to aid the decision making process. Also we analyse the rational basis and indication for the new surgical techniques such as minimally invasive coronary surgery and total arterial revascularization. Finally, the indication and timing of surgery in patients with mechanical complications of acute myocardial infarction are considered.