Liang, Jackson

Introduction: Thoracic external beam radiation therapy (XRT) for cancer is associated with a multitude of long-term cardiotoxic side effects. Previous studies have suggested worse outcomes in XRT-treated cancer survivors who undergo revascularization with CABG, but sample sizes have been small. In addition, XRT after CABG is thought to portend decreased patency and survival. We aimed to examine outcomes after CABG in patients with XRT compared with to those without XRT. Methods: We identified all patients who were treated with both CABG (between 1999 and 2013) and curative thoracic XRT for cancer (between 1971 and 2013) (>30 Gray). Baseline clinical characteristics and comorbidities at time of CABG, as well as long-term outcomes after CABG and XRT were compared with propensity matched control cohorts. Results: A total of 38 patients underwent CABG following XRT [Group 1] (mean age 67.9, 63% female) and 43 patients underwent XRT after CABG [Group 2] (mean age 69.3, 63% female). Compared with propensity-matched controls (Group 1: n=141; Group 2: n=167), baseline clinical and demographic characteristics between cases and controls were similar in both groups, except a lower incidence of triple vessel disease in XRT cases in Group 2 (64 vs 80%, p=0.02). For Group 1, there was no significant difference in all-cause survival in long-term follow-up after CABG (Fig. 1, p=0.72). Meanwhile, Group 2 cases had significantly higher all-cause mortality following XRT (Fig. 2, p<0.001). Conclusions: Patients previously treated with thoracic XRT who subsequently undergo CABG for coronary artery disease have a similar overall mortality rate compared to patients without prior XRT. This suggests that CABG is an effective method of revascularization in these patients. The higher mortality rates in CABG patients who subsequently develop disease requiring thoracic XRT is likely due to oncologic rather than cardiovascular causes, but more data are necessary to evaluate this finding.

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.

Dynamic QT Interval Monitoring Post‐LCSDBackgroundVideoscopic left cardiac sympathetic denervation (LCSD) is an adjunct therapy for reduction of arrhythmia‐induced events in patients with long‐QT syndrome (LQTS). LCSD reduces LQTS‐triggered breakthrough cardiac events. The temporal effects of QTc changes post‐LCSD have not been studied.MethodsWe utilized continuous QTc monitoring on 72 patients with LQTS. We evaluated acute and long‐term QTc changes in comparison to 12‐lead ECG‐derived QTc values prior to surgery, 24 hours postsurgery, and at follow up ≥3 months.ResultsSeventy‐two patients underwent LCSD at our institution (46% male, mean age at LCSD was 14 ± 10 years). The mean baseline, pre‐LCSD QTc was 505 ± 56 ms, which had decreased significantly at ≥3 months post‐LCSD to 491 ± 40 ms (P = 0.001). QTc monitoring revealed that the majority of the cohort (53/72; 74%) had a transient increase >30 ms in QTc from baseline, with an average maximum increase of 72 ± 30 ms. Resolution within 10 ms of baseline or less occurred in 57% (30/53) at 24 hours post‐LCSD.ConclusionsAlthough LQTS patients may have a paradoxically increased QTc post‐LCSD, the effects are transient in most patients. Importantly, no patients experienced any arrhythmias in the postoperative setting related to this transient rise in QTc.

Objectives: To retrospectively evaluate outcomes among cancer survivors previously treated with thoracic radiotherapy (RT) who later underwent percutaneous coronary intervention (PCI). Methods: From 1998 to 2012, 76 patients first received curative RT (>30 Gy, except for Hodgkin lymphoma patients) involving the heart and lungs followed by PCI. Heart and lung–specific dosimetric parameters were correlated with overall survival (OS) and cardiac-specific survival by Cox variate methods. Results: The mean interval between cancer diagnosis and PCI was 3.7 years (range, 0.1 to 12.6 y). Median follow-up since cancer diagnosis was 5.5 years. At analysis, 46 patients (61%) were alive, 5 (7%) died of cardiac causes, and 9 (12%) of cancer. Higher maximum RT heart dose was related to poorer OS since PCI (P=0.009). Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (P=0.005) and higher mean heart dose (P<0.001) were related to poorer OS since cancer diagnosis. β-Blockers, higher mean heart dose (hazard ratio [HR]=1.49, P<0.001), and percentage of targeted volume or organ receiving ≥40 Gy for heart doses (HR=1.32, P<0.001) were associated with poorer non–cancer-specific survival since cancer diagnosis. Diabetes (HR=3.84, P=0.008) and increased percentage of targeted volume or organ receiving ≥45 Gy (HR=1.01 per additional 100 cm3 irradiated, P=0.01) for the heart decreased major adverse cardiac event–free survival. Conclusions: Prior heart and lung–directed RT had volume-dependent and dose-dependent adverse effects on long-term cardiac outcomes for patients subsequently treated with PCI. RT planning that minimizes heart and lung irradiation doses should be encouraged.

Objectives: To evaluate outcomes among cancer patients with preexisting coronary artery disease and cardiac stenting who subsequently underwent thoracic radiotherapy (RT). Methods: From 1998 to 2012, 147 patients received percutaneous coronary intervention (PCI) and then curative external beam RT (>30 Gy, except for Hodgkin lymphoma patients) involving the heart and the lungs. Heart-specific and lung-specific dosimetric parameters were correlated to overall survival (OS) and cardiac-specific survival by Cox variate methods. Results: The mean interval between PCI and cancer diagnosis was 1.8 years (range, 0.1 to 14.2 y). Hypertension was present in 105 patients (71%), and hyperlipidemia in 82 (56%). At the time of analysis, 69 patients (47%) were alive, 3 (2%) died of cardiac causes, and 53 (36%) died of cancer. In multivariate analyses, OS since PCI was related to cancer type (P=0.004). Decreased OS since cancer diagnosis was related to older age (P<0.001) and increased percentage of targeted volume or organ receiving 20 Gy or more for lung (P<0.001), even after controlling for sex, cancer type, and stage. However, for non–cancer-specific survival and major adverse cardiac event-free survival, older age and underlying cardiopulmonary comorbidities dominated (rather than heart and lung dosimetric parameters) in predicting worse outcome for these patients with preexisting coronary artery disease who later underwent RT. Conclusions: Cancer type, older age, and preexisting cardiopulmonary comorbidities and risk factors most significantly predicted clinical outcome and survival for these patients with existing coronary stents who subsequently received thoracic RT. Dosimetric detrimental effects were not significant in our study.

Patients with apical ballooning syndrome may develop dynamic left ventricular outflow obstruction due to systolic anterior motion of the mitral valve leaflet and secondary functional mitral regurgitation, causing decreased cardiac output and hypotension. If suspected, bedside echocardiography will quickly confirm this complication. Positive inotropic/chronotropic agents should be avoided as they may exacerbate outflow tract obstruction, resulting in further hemodynamic compromise.

Spontaneous coronary artery dissection is an uncommon cause of chest pain and acute myocardial infarction, occurring most classically in young women without cardiovascular risk factors. We present a case of a man presenting with chest pain and arrhythmia found to have multivessel spontaneous coronary artery dissection and hyperhomocysteinemia and we raise the possibility of a potential link between the two conditions.