Case Report and Literature Review of Cardiac Amyloidosis: A Not-So-Rare Cause of Heart Failure

Restrictive cardiomyopathy secondary to cardiac amyloidosis is an underdiagnosed cause of heart failure and it is associated with significant morbidity and mortality. The most common types of amyloidosis are light chain amyloidosis, transthyretin amyloidosis and secondary amyloidosis. We report the case of a 84-year-old man that presented with new onset signs and symptoms of heart failure. Multimodality imaging with echocardiogram and bone tracer cardiac scintigraphy along with biomarkers, monoclonal proteins analysis and genetic test allowed to diagnosed a wild-type transthyretin amyloidosis. We discuss the clinical and diagnostic features and review the current literature about cardiac amyloidosis. This paper aims to increase clinicians' awareness of cardiac amyloidosis to promptly recognize, diagnose and treat it.

Right Ventricular Septal Versus Apical Pacing: Long-Term Incidence of Heart Failure and Survival

The clinical benefits of right ventricular septal (RVS) pacing compared to those of right ventricular apical (RVA) pacing are still in debate. We aimed to compare the incidence of heart failure (HF) and all-cause mortality in patients submitted to RVS and RVA pacing during a longer follow-up. This a single-center, retrospective study analysis of consecutive patients submitted to pacemaker implantation. The primary outcome was defined as the occurrence of HF during follow-up. The secondary outcome was all-cause death. A total of 251 patients were included, 47 (18.7%) with RVS pacing. RVS pacing was associated to younger age, male gender, lower body mass index, ischemic heart disease, and atrial fibrillation. During a follow-up period of 5.2 years, the primary outcome occurred in 89 (37.1%) patients. RVS pacing was independently associated with a 3-fold lower risk of HF, after adjustment. The secondary outcome occurred in 83 (34.2%) patients, and pacemaker lead position was not a predictor. Fluoroscopy time and rate of complications (rarely life-threatening) were similar in both groups. Our study points to a potential clinical benefit of RVS positioning, with a 3.3-fold lower risk of HF, without accompanying increase in procedure complexity nor complication rate.

Myocardial Bridging Leading to Cardiac Collapse in a Marathon Runner

Myocardial bridging (MB) is a congenital coronary anomaly, which is defined as cardiac muscle overlying a portion of a coronary artery. Although traditionally considered benign in nature, increasing attention is being given to specific subsets of MB. Sports medicine recognizes MB as a cause of sudden death among young athletes. We present a case of a 30-year-old man who suddenly collapsed during a marathon running. Diagnostic workup with coronary computed tomography angiography revealed the presence of three simultaneous myocardial bridges in this patient, possibly explaining the exercise-induced syncope. The other diagnostic tests excluded seizures, cranioencephalic lesions, ionic or metabolic disturbances, acute coronary syndromes, cardiomyopathies, myocarditis, or conduction disturbances. Exertional syncope is a high-risk complaint in the marathon runner. In the context of intense physical activity, the increased sympathetic tone leading to tachycardia and increased myocardial contractility facilitates MB ischemia. In this illustrative case, the patient’s syncope might probably be associated with an ischemia-induced arrhythmia secondary to MB and potentiated by dehydration in the context of prolonged stress (marathon running). In conclusion, this case highlights that MB may be associated with dangerous complications (myocardial ischemia and life-threatening ventricular arrhythmias), particularly during intense physical activity and in the presence of a long myocardial bridge.

Diabetes and pre-infarct angina. Time to rethink comorbidities in the reperfusion-injury phenomenon?

Background

Pre-infarct angina (PIA) has been shown to reduce reperfusion injury and infarct size in patients with ST-elevation myocardial infarction (STEMI) and currently represents the most efficient form of myocardial conditioning yet discovered. The role of diabetes on ischemic preconditioning remains controversial – while some pre-clinical studies suggest that diabetes blunts ischemic conditioning, clinical studies are lacking.

Methods

We retrospectively evaluated consecutive patients with STEMI admitted in our hospital from January 2008 to August 2018 who underwent primary angioplasty (PCI). PIA was defined as chest, arm or jaw pain during the preceding 48h before STEMI diagnosis. Peak creatine kinase and peak Troponin T levels were used as a surrogate of infarct size. Ischemic time (IT) was defined as the time between the onset of symptoms to the restoration of flow after either guidewire passage, thrombus aspiration or first balloon inflation.

Results

Of the 1143 included patients, 74% (n=845) were male and mean age was 62.6±13.1 years. A quarter of STEMI-patients had diabetes (25%, n=285). Almost a third of the patients (32%, n=359) had a history of angina in the preceding 48h before STEMI (PIA). The proportion of PIA was similar between diabetic and non-diabetic patients. In patients with diabetes, PIA was associated with lower creatine kinase (CK) (1144 [500–2212] vs 1715 [908–3309] U/L, p=0.0029) and Troponin T (TnT 3.30 [1.90–6.58] vs 4.88 [2.50–9.58] ng/mL, p=0.0022) despite similar IT as compared to those without PIA (328 [200–554] vs. 258 [180–530] minutes, p=0.1365). In non-diabetic patients, PIA was not significantly associated with infarct size (TnT 3.74 [2.23–7.11] vs 4.56 [2.44–7.77] ng/mL, p=0.1945; CK 1549 [910 - 2909] vs 1793 [996 - 3078] U/L, p=0.0653) even after adjustment for the increased ischemic time (240 [150–550] vs. 210 [140–405] minutes, p=0.0128) (β=−0.12, p=0.085 for CK and β=−0.11, p=0.183 for TnT). A significant interaction was observed between the existence of PIA and diabetes on peak TnT (p=0.026 for interaction) and CK (p=0.047 for interaction), which was independent of the culprit vessel and IT. During a median follow-up period of 18.0 [12.1–25.5] months, 268 (24.0%) MACE events have occurred (165 deaths, 27 strokes, 46 myocardial infarctions and 26 target vessel revascularization). PIA was associated with a significant reduction in the incidence of MACE (HR 0.66 (95% CI: 0.48–0.89)) driven by a reduction on mortality (HR 0.44 (95% CI: 0.28–0.70)). Diabetes was associated with an increased incidence of MACE (HR 1.42 (95% CI: 1.07–1.89)). No interaction was found between diabetes and PIA on their effect on MACCE events.

Conclusion

PIA is a strong predictor of favourable outcomes in the setting of STEMI. The effect of PIA on myocardial protection in patients with STEMI undergoing primary PCI seems to be modulated by the presence of diabetes.

Distribution of Peak CK and Peak TnT

Funding Acknowledgement

Type of funding source: None