Outcomes after percutaneous coronary intervention with stents in patients treated with thoracic external beam radiation for cancer

Interventional cardiology in cancer patients: A position paper from the Portuguese Cardiovascular Intervention Association and the Portuguese Cardio-Oncology Study Group of the Portuguese Society of Cardiology

The field of Cardio-Oncology has grown significantly, especially during the last decade. While awareness of cardiotoxicity due to cancer disease and/or therapies has greatly increased, much of the attention has focused on myocardial systolic disfunction and heart failure. However, coronary and structural heart disease are also a common issue in cancer patients and encompass the full spectrum of cardiotoxicity. While invasive percutaneous or surgical intervention, either is often needed or considered in cancer patients, limited evidence or guidelines are available for dealing with coronary or structural heart disease. The Society for Cardiovascular Angiography and Interventions consensus document published in 2016 is the most comprehensive document regarding this particular issue, but relevant evidence has emerged since, which render some of its considerations outdated. In addition to that, the recent 2022 ESC Guidelines on Cardio-Oncology only briefly discuss this topic. As a result, the Portuguese Association of Cardiovascular Intervention and the Cardio-Oncology Study Group of the Portuguese Society of Cardiology have partnered to produce a position paper to address the issue of cardiac intervention in cancer patients, focusing on percutaneous techniques. A brief review of available evidence is provided, followed by practical considerations. These are based both on the literature as well as accumulated experience with these types of patients, as the authors are either interventional cardiologists, cardiologists with experience in the field of Cardio-Oncology, or both.

Accelerated Atherosclerosis and Cardiovascular Toxicity Induced by Radiotherapy in Breast Cancer

The number of patients diagnosed with breast cancer and cardiovascular disease is continuously rising. Treatment options for breast cancer have greatly evolved, but radiotherapy (RT) still has a key role in it. Despite many advances in RT techniques, cardiotoxicity is one of the most important side effects. The new cardio-oncology guidelines recommend a baseline evaluation, risk stratification and follow-up of these patients. Cardiotoxicity induced by RT can be represented by almost all forms of cardiovascular disease, with atherosclerosis being the most frequent. An interdisciplinary team should manage these patients, in order to have maximum therapeutic effect and minimum cardiovascular toxicity. This review will summarize the current incidence, risk factors, mechanisms and follow-up of RT-induced cardiovascular toxicity.

Percutaneous Coronary Intervention Outcomes in Patients With Prior Thoracic Radiation Therapy: A Systematic Review and Meta-Analysis

Background

Thoracic radiation predisposes patients to accelerated coronary artery disease. There is a paucity of data in both short-term and long-term outcomes following revascularization in patients who have undergone thoracic radiation.

Methods

We performed a search of the Medline, Cochrane, and Scopus databases for studies that compared outcomes in cancer patients who have undergone thoracic radiation and percutaneous coronary intervention (PCI). The primary outcome of our meta-analysis was all-cause mortality. Secondary outcomes included cardiac mortality, myocardial infarction (MI), and restenosis.

Results

The analysis included four observational studies with a total of 13,941 patients for the primary outcome of all-cause mortality. There were a total of 1,322 patients analyzed for cardiac mortality, 13,103 for MI, and 10,530 for restenosis. The longest follow-up for the primary outcome was 16 years. There was statistically significant higher risk of all-cause mortality in patients who underwent thoracic radiation (risk ratio (RR): 1.29, 95% confidence interval (CI): 1.08 - 1.54, P = 0.004). There was no statistically significant difference in cardiac mortality (RR: 1.15, 95% CI: 0.83 - 1.61, P = 0.40), MI (RR: 1.01, 95% CI: 0.20 - 5.08, P = 0.99), and restenosis (RR: 1.92, 95% CI: 0.24 - 15.35, P = 0.54).

Conclusion

In this meta-analysis, we found a higher risk of all-cause mortality in patients with a history of thoracic radiation undergoing PCI, likely from underlying malignancy itself.

Percutaneous Coronary Angioplasty in Patients with Cancer: Clinical Challenges and Management Strategies

The number of cancer survivors in the United States is projected to increase by 31% by 2030. With advances in early screening, diagnosis and therapeutic strategies, a steadily increasing number of patients are surviving cancer. Coronary artery disease (CAD) is now one of the leading causes of death amongst cancer survivors, with the latter group of patients having a higher risk of CAD compared to the general population. Our review covers a range of specific challenges faced by doctors when considering percutaneous coronary interventions (PCI) in cancer patients; clinical outcomes in cancer patients undergoing PCI, as well as some important technical considerations to be made when making decisions regarding the management strategy in this special population of patients.

Radiotherapy-induced isolated left main coronary artery disease presenting with cardiogenic shock: A case report

RATIONALE

Mediastinal radiotherapy is a common practice for treating breast cancer and Hodgkin's lymphoma. Radiotherapy causes cardiovascular damage and has attracted increasing attention, particularly among Hodgkin's lymphoma patients, as they receive a higher dose of radiation.

PATIENT CONCERNS

A 36-year-old woman with a past medical history of Hodgkin's lymphoma presented with persistent chest pain for 3 hours. She experienced exertional chest pain 1 month before when she was climbing stairs, which disappeared after a few minutes with rest, but recurred with a similar level of exertion. Three hours before admission to the emergency room, the chest pain persisted and was accompanied by diaphoresis and dyspnea.

DIAGNOSIS

Cardiogenic shock caused by radiotherapy-induced left main coronary artery disease.

INTERVENTIONS

Urgent angiography revealed left main coronary artery stenosis. Intravascular ultrasonography showed diffuse fibrous proliferation in the left main coronary artery. Hemodynamic instability was resolved after drug-eluting stent implantation.

OUTCOMES

The patient was discharged uneventfully 5 days after the procedure, with a prescription for dual antiplatelet and statin therapy. She was asymptomatic with good exercise tolerance at the 3-month follow-up.

CONCLUSION

Radiotherapy-induced isolated left main coronary artery disease is a rare complication of cancer radiotherapy and can occur years or decades after treatment. Fibrous proliferation is a characteristic pathologic change in the exposed coronary arteries.

Cardiovascular Manifestations From Therapeutic Radiation: A Multidisciplinary Expert Consensus Statement From the International Cardio-Oncology Society

Radiation therapy is a cornerstone of cancer therapy, with >50% of patients undergoing therapeutic radiation. As a result of widespread use and improved survival, there is increasing focus on the potential long-term effects of ionizing radiation, especially cardiovascular toxicity. Radiation therapy can lead to atherosclerosis of the vasculature as well as valvular, myocardial, and pericardial dysfunction. We present a consensus statement from the International Cardio-Oncology Society based on general principles of radiotherapy delivery and cardiovascular risk assessment and risk mitigation in this population. Anatomical-based recommendations for cardiovascular management and follow-up are provided, and a priority is given to the early detection of atherosclerotic vascular disease on imaging to help guide preventive therapy. Unique management considerations in radiation-induced cardiovascular disease are also discussed. Recommendations are based on the most current literature and represent a unanimous consensus by the multidisciplinary expert panel.

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Radiation therapy leads to short- and long-term cardiovascular adverse effects of the vasculature and the heart, including valvular, myocardial, and pericardial disease.

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Computed tomography scans conducted for radiation planning or cancer staging provide an available opportunity to detect asymptomatic atherosclerosis and direct preventive therapies.

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Additional practical screening recommendations for cardiovascular disease based on anatomical exposure are provided.

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There are unique considerations in the management of radiation-induced cardiovascular disease; contemporary percutaneous treatment is often preferred over surgical options.

Coronary revascularisation outcomes in patients with cancer

Cancer and coronary artery disease (CAD) overlap in traditional risk factors as well as molecular mechanisms underpinning the development of these two disease states. Patients with cancer are at increased risk of developing CAD, representing a high-risk population that are increasingly undergoing coronary revascularisation. Over 1 in 10 patients with CAD that require revascularisation with either percutaneous coronary intervention or coronary artery bypass grafting have either a history of cancer or active cancer. These patients are typically older, have more comorbidities and have more extensive CAD compared with patients without cancer. Haematological abnormalities with competing risks of thrombosis and bleeding pose further unique challenges during and after revascularisation. Management of patients with concurrent cancer and CAD requiring revascularisation is challenging as these patients carry a higher risk of morbidity and mortality compared with those without cancer, often driven by the underlying cancer and associated comorbidities. However, due to variability by different types and stages of cancer, revascularisation outcomes are specific to cancer characteristics such as the timing of onset, cancer subtype and site, stage, presence of metastases, and cancer-related therapies received. Recent studies have provided insights into defining revascularisation outcomes, procedural considerations and best practices in managing patients with cancer. Nevertheless, many gaps remain that require further studies to inform clinical best practices in this population.

Coronary artery disease in patients with cancer: challenges and opportunities for improvement

PURPOSE OF REVIEW

Coronary artery disease (CAD) is a common comorbidity in patients with cancer. We review shared risk factors between the two diseases and cancer treatments that increase the risk of CAD. We also discuss outcomes and management considerations of patients with cancer who develop CAD.

RECENT FINDINGS

Several traditional and novel risk factors promote the development of both CAD and cancer. Several cancer treatments further increase the risk of CAD. The presence of cancer is associated with a higher burden of comorbidities and thrombocytopenia, which predisposes patients to higher bleeding risks. Patients with cancer who develop acute coronary syndromes are less likely to receive timely revascularization or appropriate medical therapy, despite evidence showing that receipt of these interventions is associated with substantial benefit. Accordingly, a cancer diagnosis is associated with worse outcomes in patients with CAD. The risk-benefit balance of revascularization is becoming more favorable due to the improving prognosis of many cancers and safer revascularization strategies, including shorter requirements for dual antiplatelet therapy after revascularization.

SUMMARY

Several factors increase the complexity of managing CAD in patients with cancer. A multidisciplinary approach is recommended to guide treatment decisions in this high-risk and growing patient group.

Radiation-Induced Vascular Disease-A State-of-the-Art Review

Since the 1990s, there has been a steady increase in the number of cancer survivors to an estimated 17 million in 2019 in the US alone. Radiation therapy today is applied to a variety of malignancies and over 50% of cancer patients. The effects of ionizing radiation on cardiac structure and function, so-called radiation-induced heart disease (RIHD), have been extensively studied. We review the available published data on the mechanisms and manifestations of RIHD, with a focus on vascular disease, as well as proposed strategies for its prevention, screening, diagnosis, and management.

Contemporary Understandings of Cardiovascular Disease After Cancer Radiotherapy: a Focus on Ischemic Heart Disease

PURPOSE OF REVIEW

Radiation-induced cardiovascular disease, including coronary artery disease, is a well-known sequela of radiation therapy and represents a significant source of morbidity and mortality for cancer survivors. This review examines current literature and guidelines to care for this growing population of cancer survivors.

RECENT FINDINGS

The development of radiation-induced ischemic heart disease following radiation can lead even to early cardiotoxicities, inclusive of coronary artery disease, which limit cancer treatment outcomes. These coronary lesions tend to be diffuse, complex, and proximal. Early detection with multimodality imaging and targeted intervention is required to minimize these risks. Early awareness, detection, and management of radiation-induced cardiovascular disease are paramount as cancer survivorship continues to grow.

Vascular toxic effects of cancer therapies

Cancer therapies can lead to a broad spectrum of cardiovascular complications. Among these, cardiotoxicities remain of prime concern, but vascular toxicities have emerged as the second most common group. The range of cancer therapies with a vascular toxicity profile and the clinical spectrum of vascular toxic effects are quite broad. Historically, venous thromboembolism has received the greatest attention but, over the past decade, the arterial toxic effects, which can present as acute vasospasm, acute thrombosis and accelerated atherosclerosis, of cancer therapies have gained greater recognition. This Review focuses on these types of cancer therapy-related arterial toxicity, including their mechanisms, and provides an update on venous thromboembolism and pulmonary hypertension associated with cancer therapies. Recommendations for the screening, treatment and prevention of vascular toxic effects of cancer therapies are outlined in the context of available evidence and society guidelines and consensus statements. The shift towards greater awareness of the vascular toxic effects of cancer therapies has further unveiled the urgent needs in this area in terms of defining best clinical practices. Well-designed and well-conducted clinical studies and registries are needed to more precisely define the incidence rates, risk factors, primary and secondary modes of prevention, and best treatment modalities for vascular toxicities related to cancer therapies. These efforts should be complemented by preclinical studies to outline the pathophysiological concepts that can be translated into the clinic and to identify drugs with vascular toxicity potential even before their widespread clinical use.

Acute coronary syndromes in cancer patients

: Cardiovascular disease and cancer are responsible for the majority of deaths in the Western world. These two entities share common risk factors and their intersection will be more and more frequent in future due to general population aging and long-term cancer control. Clinical presentation, management and outcome of acute coronary syndromes (ACS) in cancer patients could differ from noncancer ones. Cancer patients were frequently excluded from clinical trials and so the paucity of data further complicates the scenario. The management of ACS in cancer patients represents a unique setting in which the risk/benefit ratio of invasive treatment should be carefully evaluated. This review focused on the available evidence of all aspects of ACS in cancer patients providing a guide to a multidisciplinary approach.

Prognosis of acute coronary syndromes after radiotherapy for breast cancer

BACKGROUND AND PURPOSE

Breast cancer patients treated with radiotherapy are at increased risk of subsequent acute coronary syndromes (ACS). We aimed to study if radiotherapy also influences the prognosis of these ACS.

MATERIALS AND METHODS

We included all 398 patients diagnosed with ACS following radiotherapy from our hospital-based cohort of early breast cancer patients aged <71 years, treated 1970-2009. Cardiovascular disease incidence and cause of death were acquired through questionnaires to general practitioners and cardiologists. Internal mammary chain (IMC) irradiation delivers the highest heart doses in breast cancer radiotherapy. Hence, we compared ACS prognosis between patients treated with/without IMC-irradiation. ACS prognosis was assessed through cardiac death, death due to ACS and cardiovascular disease incidence, using multivariable Cox proportional hazard models and by estimating cumulative incidence.

RESULTS

In total, 62% of patients with ACS had received IMC-irradiation and 38% did not (median age at ACS diagnosis, 67 years). Median time between breast cancer and ACS was 15 years. After ACS, ten-year cumulative risk of cardiac death was 35% for patients who had IMC-irradiation (95% confidence interval [95%CI] 29-41) compared to 24% (95%CI 17-31) for patients without IMC-irradiation (p = 0.04). After correction for confounders, IMC-irradiation remained associated with a less favourable prognosis of ACS compared to no IMC-irradiation (hazard ratio cardiac death = 1.7, 95%CI 1.1-2.5).

CONCLUSION

Our results suggest that radiotherapy, in case of substantial heart doses,may worsen ACS prognosis. This is an important, novel finding that may impact upon the risk-based care for breast cancer survivors with ACS.

Radiation-Associated Cardiac Disease: A Practical Approach to Diagnosis and Management

Radiation-associated cardiac disease (RACD) results in complex clinical presentations, unique management issues, and increased morbidity and mortality. Patients typically present years or even decades after radiation exposure, with delayed-onset cardiac damage sustained from high cumulative doses. Multimodality imaging is crucial to determine the manifestations and severity of disease because symptoms are often nonspecific. Comprehensive screening using a coordinated approach may enable early detection. However, timing of intervention should be carefully considered in these patients because surgery is often complex and high-risk second surgeries should be minimized in the long-term. This review aims to provide treating physicians with a comprehensive and clinically focused overview of RACD, including clinical/imaging manifestations, multi-modality screening recommendations, and management options.

Angiographic predictors of adverse outcomes after percutaneous coronary intervention in patients with radiation associated coronary artery disease

OBJECTIVES

To determine procedural predictors of long-term outcomes for patients with radiation associated coronary artery disease (CAD) treated with percutaneous coronary intervention (PCI).

BACKGROUND

Patients who develop CAD after external beam radiation therapy (XRT) for cancer are at high-risk for adverse events following PCI. It is unknown if specific angiographic features can predict outcomes in this population.

METHODS

This is an observational study of 157 patients with malignancy who received XRT prior to PCI. Rates of major adverse cardiovascular and cerebrovascular events (MACCEs; all-cause mortality, myocardial infarction, repeat revascularization, or stroke) were compared across patient characteristics over time with the Cox proportional hazards and Kaplan-Meier's analyses.

RESULTS

During follow-up of 5.4 ± 4.5 years, 91 (58%) patients had MACCE. On Kaplan-Meier's analysis of angiographic characteristics, MACCE was more frequent in patients with at least moderate target vessel calcification (P = 0.023), ostial stenosis (P = 0.049), target vessel diameter ≥ 3.0 mm (P = 0.018), a SYNTAX score ≥ the median of 11 (P = 0.014), or bare metal stenting (BMS)/balloon angioplasty (BA) compared to drug-eluting stenting (DES) (P = 0.006). Cardiac death was more frequent in patients with SYNTAX score ≥ 11 (P = 0.028) or BMS (P = 0.043). After multivariable adjustment for both angiographic and clinical characteristics, independent predictors of MACCE were BMS placement (P = 0.013), chronic kidney disease ≥ stage 3 (P = 0.019), New York Heart Association (NYHA) heart failure class ≥3 (P = 0.034), and SYNTAX score ≥ 11 (P = 0.041).

CONCLUSIONS

In patients previously exposed to XRT treated with PCI, independent angiographic predictors of MACCE include SYNTAX score ≥ 11 and BMS placement, suggestive that DES should be preferred in this population.

Radiation-Induced Coronary Artery Disease and Its Treatment: A Quick Review of Current Evidence

As advances in medical technology arise and the availability of cancer treatment increases, an increased number of patients are receiving cancer treatment. Radiation therapy has evolved to become one of the cornerstones of treatment for various types of cancers. One of the long-term consequences of radiation therapy is radiation-induced coronary artery disease (RICAD). Although the pathophysiology of RICAD may be slightly different and more acute onset than the commonly seen “generic” coronary artery disease, it is common practice to treat RICAD in the same method as nonradiation-induced CAD. This paper summarizes the current research available on the topic and shows there is not enough research to obtain significant data about outcomes and restenosis rates of PCI or outcomes of CABG in RICAD. The aim of this review is to create a concise and easy-to-follow review of the relevant data regarding RICAD and hopefully spark further interest in future studies in this field.

Acute Coronary Syndrome Management in Cancer Patients

PURPOSE OF REVIEW

Coronary artery disease and cancer often co-exist. Patients with cancer have been excluded by most major cardiology trials and registries and their management remains largely empiric. Cancer patients experience an approximately 10-times increased mortality compared to the general population. Conservative therapy of ACS in cancer therapy results in 1-year mortality of 74%. This review article aims to describe the mechanisms of acute coronary syndromes in cancer patients, their clinical presentation, and their management.

RECENT FINDINGS

Newer studies have shed light on the mechanisms of ACS in cancer patients, which are different and related to the type of malignancy and its associated therapy. Medication-specific coronary effects (vasospasm, endothelial dysfunction, spontaneous thrombosis, accelerated atherosclerosis), radiation vasculitis, cancer cell coronary embolism, and coronary compression from thoracic malignancies are unique ACS mechanisms in cancer patients. Close collaboration between oncologists and cardiologists for thoughtful patient selection and decision making strategies is necessary to provide optimal medical care.

Re-Evaluating the Safety of Drug-Eluting Stents in Cancer Patients

Evidence increasingly shows that cancer and coronary artery disease are interlinked through common risk factors, co-occurrence in an aging population, and through the deleterious effects of cancer treatment on cardiovascular health. Many of the clinical risk factors for cancer, such as diabetes, smoking, and chronic inflammatory state, are also risk factors for coronary artery disease and for stent restenosis and thrombosis. The current generations of drug-eluting stents have been proven to reduce the risk of restenosis and stent thrombosis as compared with bare-metal stents. However, because of the perceived need for shorter course of dual antiplatelet treatment, operators often prefer bare-metal stents in patients with cancer out of concern for increased bleeding risk and expectant need for cancer-directed surgery. The current evidence with newer-generation stent technology demonstrates the feasibility of shorter duration of dual antiplatelet treatment, without increasing the risk of stent thrombosis and bleeding, while maintaining improved efficacy compared with bare-metal stents. Cardiovascular disease in patients with cancer is complex, and treatment needs to be individualized. Refraining from the use of drug-eluting stents altogether in this rapidly expanding cohort may lead to higher major adverse cardiovascular events, which can thwart the effectiveness of advances in both cancer and cardiovascular therapeutics. Considering the developing evidence thus far, perhaps it is time to rethink the choice of stent in patients with cancer who undergo percutaneous coronary intervention.

How to prevent and manage radiation-induced coronary artery disease

Radiation-induced coronary heart disease (RICHD) is the second most common cause of morbidity and mortality in patients treated with radiotherapy for breast cancer, Hodgkin's lymphoma and other prevalent mediastinal malignancies. The risk of RICHD increases with radiation dose. Exposed patients may present decades after treatment with manifestations ranging from asymptomatic myocardial perfusion defects to ostial, triple-vessel disease and sudden cardiac death. RICHD is insidious, with a long latency and a tendency to remain silent late into the disease course. Vessel involvement is often diffuse and is preferentially proximal. The pathophysiology is similar to that of accelerated atherosclerosis, characterised by the formation of inflammatory plaque with high collagen and fibrin content. The presence of conventional risk factors potentiates RICHD, and aggressive risk factor management should ideally be initiated prior to radiation therapy. Stress echocardiography is more sensitive and specific than myocardial perfusion imaging in the detection of RICHD, and CT coronary angiography shows promise in risk stratification. Coronary artery bypass grafting is associated with higher risks of graft failure, perioperative complications and all-cause mortality in patients with RICHD. In most cases, the use of drug-eluting stents is preferable to surgical intervention, bare metal stenting or balloon-angioplasty alone.

Coronary artery bypass grafting in patients treated with thoracic radiation: a case-control study

Background and aim

Thoracic radiation therapy (XRT) for cancer is associated with the development of significant coronary artery disease that may require coronary artery bypass grafting surgery (CABG). Contemporary acute surgical outcomes and long-term postoperative survival of patients with prior XRT have not been well characterised.

Methods

This was a retrospective, single-centre study of patients with a history of thoracic XRT who required CABG and who were propensity matched against 141 controls who underwent CABG over the same time period. The objectives were to assess early CABG outcomes and long-term survival in patients with prior XRT.

Results

Thirty-eight patients with a history of previous thoracic XRT underwent CABG from 1994 to 2013. The median time from XRT exposure to surgery was 7.9 years (IQR: 2.5–18.4 years). Perioperative adverse events were similar in the XRT group and controls; however, there was a trends lower utilisation of internal mammary artery (IMA) grafts in the XRT group (89%vs98%, P=0.13). After a median postoperative follow-up of 5.4 years (IQR 0.9–9.4 years), no difference in long-term all-cause mortality was observed.

Conclusion

Patients with prior thoracic XRT who undergo CABG have similar long-term all-cause mortality compared with controls. Isolated CABG after thoracic XRT is not associated with higher perioperative complications, but IMA graft use may be limited by prior XRT.

Percutaneous revascularization in patients treated with thoracic radiation for cancer

OBJECTIVES

To assess coronary revascularization outcomes in patients with previous thoracic radiation therapy (XRT).

BACKGROUND

Previous chest radiation has been reported to adversely affect long term survival in patients with coronary disease treated with percutaneous coronary interventions (PCI).

METHODS

Retrospective, single center cohort study of patients previously treated with thoracic radiation and PCI. Patients were propensity matched against control patients without radiation undergoing revascularization during the same time period.

RESULTS

We identified 116 patients with radiation followed by PCI (XRT-PCI group) and 408 controls. Acute procedural complications were similar between groups. There were no differences in all-cause and cardiac mortality between groups (all-cause mortality HR 1.31, P=.078; cardiac mortality 0.78, P=.49).

CONCLUSION

Patients with prior thoracic radiation and coronary disease treated with PCI have similar procedural complications and long term mortality when compared to control subjects.

[Radiation-related heart toxicity: Update in women]

Breast cancer is a common diagnosis in women and thus women are at risk of radiation-induced heart disease, in particular during radiotherapy for left breast cancer and when the internal mammary chain is included. Rates of major cardiac events increase with younger age at the time of irradiation, diagnosis before 1990s, higher radiation doses, coexisting cardiovascular risk factors and adjuvant cardiotoxic chemotherapy. Radiation-induced heart disease comprises a spectrum of cardiac pathologies, including pericardial disease, cardiomyopathy, coronary artery disease and valvular disease. The cardiac injury can appear a long time after radiotherapy and can consist of complex lesions with poor prognosis. The disciplines of cardiology and oncology have increasingly recognized the benefits of collaborating in the care of cancer patients with cardiac disease, developing guidelines for the assessment and management of radiation-related cardiovascular disease. We could consider screening patients with previous chest radiation every 5 years with transthoracic echocardiography and functional imaging. However, prevention remains the primary goal, using cardiac sparing doses and avoidance techniques in radiotherapy to improve patient survival.

Novel concepts in radiation-induced cardiovascular disease

Radiation-induced cardiovascular disease (RICVD) is the most common nonmalignant cause of morbidity and mortality among cancer survivors who have undergone mediastinal radiation therapy (RT). Cardiovascular complications include effusive or constrictive pericarditis, cardiomyopathy, valvular heart disease, and coronary/vascular disease. These are pathophysiologically distinct disease entities whose prevalence varies depending on the timing and extent of radiation exposure to the heart and great vessels. Although refinements in RT dosimetry and shielding will inevitably limit future cases of RICVD, the increasing number of long-term cancer survivors, including those treated with older higher-dose RT regimens, will ensure a steady flow of afflicted patients for the foreseeable future. Thus, there is a pressing need for enhanced understanding of the disease mechanisms, and improved detection methods and treatment strategies. Newly characterized mechanisms responsible for the establishment of chronic fibrosis, such as oxidative stress, inflammation and epigenetic modifications, are discussed and linked to potential treatments currently under study. Novel imaging modalities may serve as powerful screening tools in RICVD, and recent research and expert opinion advocating their use is introduced. Data arguing for the aggressive use of percutaneous interventions, such as transcutaneous valve replacement and drug-eluting stents, are examined and considered in the context of prior therapeutic approaches. RICVD and its treatment options are the subject of a rich and dynamic body of research, and patients who are at risk or suffering from this disease will benefit from the care of physicians with specialty expertise in the emerging field of cardio-oncology.

Long-Term Mortality in Patients With Radiation-Associated Coronary Artery Disease Treated With Percutaneous Coronary Intervention

Background—

The incidence and predictors of long-term mortality after percutaneous coronary intervention (PCI) for radiation-associated coronary artery disease are unknown.

Methods and Results—

In this observational study of 314 patients (age, 65.2±11.4 years; 233 [74%] women) treated with PCI, 157 patients with previous external beam radiation therapy (XRT) were matched 1:1 with 157 comparison patients with atherosclerotic coronary artery disease without previous XRT, based on age, sex, lesion artery, and PCI type. The primary end point was all-cause mortality, and the secondary end point was cardiovascular mortality. After follow-up of 6.6±5.5 years, there were 101 deaths; 59 in the XRT group and 42 in the comparison group ( P =0.04). On Cox proportional hazards multivariable survival analysis, previous XRT remained an independent predictor of all-cause mortality (hazard ratio [HR] 1.85; 95% confidence interval [CI], 1.21–2.85; P =0.004) and cardiovascular mortality (HR, 1.70; 95% CI, 1.06–2.89; P =0.03). Additional independent predictors of increased all-cause mortality included balloon angioplasty or bare-metal stent placement compared with drug-eluting stent placement (HR, 2.50; 95% CI, 1.61–3.97; P <0.0001), SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) score of ≥11 (the sample median; HR, 1.99; 95% CI, 1.32–3.04; P <0.001), New York Heart Association functional class ≥3 (HR, 1.83; 95% CI, 1.15–2.91; P =0.012), history of smoking (HR, 1.88; 95% CI, 1.10–3.09; P =0.022), and age ≥65 years (HR, 1.70; 95% CI, 1.07–2.07; P =0.024).

Conclusions—

Compared with patients with typical atherosclerotic coronary artery disease, patients with radiation-associated coronary artery disease are at higher risk for mortality after PCI. Previous XRT exposure is independently associated with increased all-cause and cardiovascular mortality in patients treated with PCI.

Long-Term Outcomes in Survivors of Early Ventricular Arrhythmias After Acute ST-Elevation and Non-ST-Elevation Myocardial Infarction Treated With Percutaneous Coronary Intervention

Guidelines do not recommend an implantable cardioverter defibrillator (ICD) for prevention of sudden death in patients who develop ventricular arrhythmia (VA) within 48 hours of acute myocardial infarction (AMI) if they are successfully revascularized. We aimed to determine long-term survival in a cohort of early VA survivors treated with percutaneous coronary intervention (PCI) and to determine whether certain high-risk characteristics predicted worse outcomes. This retrospective study included all patients with early VA after AMI treated with PCI at our institution from 2002 to 2012 who survived to hospital discharge. Patients who had an ICD before their index AMI and those who received ICD before hospital discharge were excluded. Overall survival in the early VA survivors was analyzed based on post-MI left ventricular ejection fraction (LVEF) (≥50% vs <50%), MI type (ST-segment elevation myocardial infarction [STEMI] vs non-ST-segment elevation myocardial infarction [NSTEMI]), and single-vessel versus multivessel disease. Baseline presenting clinical and PCI characteristics plus outcomes were compared with matched controls with PCI-treated AMI but no early VA. Of the 79 early VA survivors treated with PCI, there were no significant differences in long-term overall survival between AMI type (STEMI vs NSTEMI), single-vessel versus multivessel disease, and LVEF at time of MI (>50% vs <50%). Despite having lower presenting LVEF (46% vs 55%, p <0.001) and higher rates of cardiogenic shock (28% vs 4%; p <0.001), survivors of early VA had similar overall survival compared with PCI-treated controls whose post-AMI hospital course was not complicated by early VA (p = 0.61). In conclusion, patients with early VA treated with PCI who survive to discharge were more likely to have STEMI, lower LVEF, and cardiogenic shock. Type of AMI or the presence of systolic dysfunction or multivessel disease did not predict long-term mortality. With early PCI, early VA survivors have similar long-term prognosis compared with those without early VA.