Hedgepeth, Chester M.

Background: Diagnosis of Takotsubo’s Cardiomyopathy (TC) remains a challenge due to similar presentation to acute coronary syndrome. Coronary catheterization (CC) proven clean coronaries is important to diagnose TC. However, it is not uncommon that CC is occasionally delayed due to unstable medical condition and/or high risk for CC. We hypothesized that patients with TC had similar outcomes whether they underwent CC at presentation or were diagnosed using non-invasive imaging techniques. Methods: Retrospective chart review of data from Memorial Hospital of Rhode Island and Kent Hospital, two community based hospitals, from June 2008 to March 2016 was done. Thirty nine adult patients > 18 years of age admitted to the intensive care unit or medical floor with chest pain, shortness of breath, elevated troponin, EKG changes, and new non-regional wall motion abnormalities or reduce ejection fraction, with suspected TC were enrolled. Patients were divided into 2 groups based on diagnostic approach of TC: Baseline echo findings suggestive of TC with EF improvement at follow up (non-CC) vs. clean coronaries by CC. Outcomes of the two groups were compared using Chi-square analysis, analysis of variance (ANOVA) and Mann-Whitney Test appropriately. Results: Out of 39 patients, 20 underwent CC while 19 did not. Mean age was not different between the 2 groups (69.1±11.8 vs. 62.4±14.0, p= NS) but CC group had more females (95 %, 19 of 20 vs 68.4%, 13 of 19; p=0.031). Most common chief complaint at the time of admission in both groups was shortness of breath (60.0%, 12 of 20 vs 68.4%, 13 of 19; p=0.548). Admission heart rate was significantly higher in non-CC vs. CC patients (102.3± 19.3 vs 85.4±85.4; p=0.007). Third troponin was higher in non-CC group (1.926 ± 2.667 vs 0.775± 1.378, p=0.017). All other admission and in-hospital findings and drug management in both groups were similar. Both CC and non-CC groups had comparable outcomes: intubation (15%, 3 of 20 vs 21.1%, 4 of 19) , heart failure (21.2 %, 4 of 20 vs 15.8%, 3 of 19), shock (0 %, 0 of 20 vs 5.3% 1 of 19 ), stroke (5 %, 1 of 20 vs 0%, 0 of 19), death (5.3 % 1 of 20 vs 5.3% 1 of 19 ), recovery (65%,13 of 20 vs 52.9 % 10 of 19) p=NS for all. ICU admission (42.1%, 8 of 20 vs 52.6%, 10 of 19; p=NS) and length of stay (8.21±7.82 days vs 5.75±5.67 days; p=NS) was not significantly different between the 2 groups. Both groups showed analogous improvement in ejection fraction (21.92 ± 13.96 vs 20.63 ± 13.21; p= 0.835) on a follow up Echo done within 2 weeks to 6 months. Conclusion: This study shows no difference in outcomes between TC patients diagnosed with CC or TTE on admission. However, CC should still be done on admission for diagnosis of TC until large non-invasive diagnostic imaging modalities (such as myocardial perfusion echocardiogram) trials show high specificity for diagnosis of TC.

Background— Ranolazine, a piperazine derivative, reduces ischemia via inhibition of the late phase of the inward sodium current (late I Na ) during cardiac repolarization, with a consequent reduction in intracellular sodium and calcium overload. Increased intracellular calcium leads to both mechanical dysfunction and electric instability. Ranolazine reduces proarrhythmic substrate and triggers such as early afterdepolarization in experimental models. However, the potential antiarrhythmic actions of ranolazine have yet to be demonstrated in humans. Methods and Results— The Metabolic Efficiency With Ranolazine for Less Ischemia in Non–ST-Elevation Acute Coronary Syndrome (MERLIN)–Thrombolysis in Myocardial Infarction (TIMI) 36 (MERLIN-TIMI 36) trial randomized 6560 patients hospitalized with a non–ST-elevation acute coronary syndrome to ranolazine or placebo in addition to standard therapy. Continuous ECG (Holter) recording was performed for the first 7 days after randomization. A prespecified set of arrhythmias were evaluated by a core laboratory blinded to treatment and outcomes. Of the 6560 patients in MERLIN-TIMI 36, 6351 (97%) had continuous ECG recordings that could be evaluated for arrhythmia analysis. Treatment with ranolazine resulted in significantly lower incidences of arrhythmias. Specifically, fewer patients had an episode of ventricular tachycardia lasting ≥8 beats (166 [5.3%] versus 265 [8.3%]; P <0.001), supraventricular tachycardia (1413 [44.7%] versus 1752 [55.0%]; P <0.001), or new-onset atrial fibrillation (55 [1.7%] versus 75 [2.4%]; P =0.08). In addition, pauses ≥3 seconds were less frequent with ranolazine (97 [3.1%] versus 136 [4.3%]; P =0.01). Conclusions— Ranolazine, an inhibitor of late I Na , appears to have antiarrhythmic effects as assessed by continuous ECG monitoring of patients in the first week after admission for acute coronary syndrome. Studies specifically designed to evaluate the potential role of ranolazine as an antiarrhythmic agent are warranted.