Man-Hong Jim

Amiodarone-Induced Thyrotoxicosis Is a Predictor of Adverse Cardiovascular Outcome

BACKGROUND Amiodarone-induced thyrotoxicosis (AIT) is a clinical condition that is notoriously difficult to manage; the relative risk of adverse cardiovascular events in these patients compared with euthyroid patients is largely unknown. OBJECTIVE We compared the clinical characteristics and major adverse cardiovascular events (MACE) in AIT and euthyroid patients. METHOD Patients at a tertiary referral center who had been prescribed amiodarone for at least 3 months were retrospectively analyzed. Baseline clinical characteristics, laboratory parameters, and outcome events were evaluated. MACE was defined as cardiovascular mortality, myocardial infarction, stroke and heart failure, or ventricular arrhythmias that required hospitalization. RESULTS A total of 354 patients (61.8 +/- 14.1 yr; 64.7% male) with a mean follow-up of 48.6 +/- 26.7 months were studied. AIT, euthyroid status, and amiodarone-induced hypothyroidism were identified in 57 (16.1%), 224 (63.3%), and 73 (20.6%) patients, respectively. No differences in baseline clinical characteristics were observed between AIT and euthyroid patients. Nonetheless AIT patients demonstrated a higher MACE rate (31.6 vs. 10.7%, P < 0.01), mostly driven by a higher rate of ventricular arrhythmias that required admission (7.0 vs. 1.3%, P = 0.03). Cox-regression multivariate analysis revealed that AIT (hazard ratio 2.68; confidence interval 1.53-4.68; P < 0.01) and left ventricular ejection fraction less than 45% (hazard ratio 2.52; confidence interval 1.43-4.42; P < 0.01) were independent predictors of MACE. CONCLUSION In patients prescribed long-term amiodarone therapy, occurrence of AIT is associated with a 2.7-fold increased risk of MACE. Regular and close biochemical surveillance is thus advisable to identify and treat this high-risk group of patients.

A new ECG criterion to identify takotsubo cardiomyopathy from anterior myocardial infarction: role of inferior leads

With the exception of contrast-enhanced cardiovascular magnetic resonance imaging, clear distinction of takotsubo cardiomyopathy from anterior wall myocardial infarction cannot be achieved currently by simple and noninvasive tests. The aim of this study was to examine the role of inferior ECG leads in distinguishing these two conditions. From January 2004 to June 2006, eight female patients suffering from takotsubo cardiomyopathy were identified by the Mayo Clinic criteria. The clinical and ECG features were compared with 27 consecutive sex- and age-matched patients with anterior wall myocardial infarction admitted to the Coronary Care Unit within the same period. The observed ECG features were then verified with that of 62 published cases of takotsubo cardiomyopathy. Takotsubo cardiomyopathy patients had similar left ventricular ejection fraction (35.0% ± 5.7% vs 38.2% ± 6.4%, P = 0.829), lower peak creatinine kinase level (461 ± 330 U/l vs 2723 ± 1826 U/l, P = 0.020), more ST-segment elevation in the inferior leads (50% vs 7.4%, P = 0.016), and virtually no ST-segment depression in inferior leads (0% vs 48.2%, P = 0.015) compared with patients who had anterior wall myocardial infarction. ST-segment elevation of ≥1.0 mm in lead II had 62.5% sensitivity and 92.6% specificity in detecting takotsubo cardiomyopathy. The observed ECG characteristics were comparable with those in the literature. In patients who present with anterior wall myocardial infarction, the absence of ST-segment depression or ST-segment elevation in inferior leads, especially if the ST-segment in lead II ≥ III, is highly suggestive of takotsubo cardiomyopathy.

Risk of ischemic stroke after new-onset atrial fibrillation in patients with hyperthyroidism

BACKGROUND Hyperthyroidism is one of the most common reversible causes of atrial fibrillation (AF); nevertheless, the risk of ischemic stroke in patients with hyperthyroidism who present with new-onset AF is unclear. OBJECTIVE This study sought to investigate the clinical outcome of hyperthyroidism-induced AF with regard to risk of ischemic stroke risk. METHODS We prospectively studied the incidence, time course, and clinical predictors for ischemic stroke in patients with hyperthyroidism-induced AF (n = 160). They were compared with age- and sex-matched cohorts of hyperthyroid patients without AF (n = 160) and AF patients without hyperthyroidism (n = 160). RESULTS Baseline characteristics were comparable among the 3 groups. At 1 year, 86 hyperthyroid patients with AF (54%) and 92 patients with nonthyroid AF (58%) had spontaneous or pharmacological sinus conversion (P = .20). Ischemic stroke was observed in 15 hyperthyroid patients with AF (9.4%) versus 5 patients with nonthyroid AF (3.1%, P = .02), and 1 hyperthyroid patient without AF (0.6%, P < .001). Furthermore, the majority of ischemic stroke (>70%) in patients with AF occurred within the first 30 days of presentation, whereas AF was still present. Cox regression analysis showed that hyperthyroidism (hazard ratio [HR]: 3.5, 95% confidence interval [CI]: 1.15 to 10.42, P = .03) and persistent AF (HR: 13.0, 95% CI: 2.88 to 58.80, P < .01) predicted the occurrence of ischemic stroke; warfarin therapy reduced the risk of ischemic stroke (HR: 0.17, 95% CI: 0.04 to 0.79, P = .02). CONCLUSION In hyperthyroid patients who presented with new-onset AF, there was an increased risk of ischemic stroke clustering during the initial phase of presentation. This should prompt early use of anticoagulation therapy in hyperthyroid patients with AF.

Recurrent acute heart failure caused by sliding hiatus hernia

The case is reported of a 75 year old woman who presented with recurrent nocturnal episodes of acute pulmonary oedema. The cause was uncertain as she had normal cardiothoracic ratio on chest radiography and normal left ventricular systolic and diastolic function by transthoracic echocardiogram. Another transthoracic echocardiogram was repeated when she was recumbent for an hour and had a full stomach. It showed a striking finding of severe left atrial compression by an external structure. Computed tomography of the thorax showed an intrathoracic mass behind the left atrium causing external compression of the left atrium suggestive of a sliding hiatus hernia. Cardiac catheterisation confirmed the diagnosis by showing a pronounced rise of pulmonary capillary wedge pressure in the recumbent position compared with the sitting up position.

Comparison of atrial fibrillation recurrence rates after successful electrical cardioversion in patients with hyperthyroidism-induced versus non-hyperthyroidism-induced persistent atrial fibrillation.

Hyperthyroidism-induced atrial fibrillation (AF) often spontaneously reverts to sinus rhythm after the return of euthyroid state, but a significant number of patients remain in persistent AF, which requires electrical cardioversion. The long-term outcome of hyperthyroidism-induced persistent AF after successful cardioversion remains unclear. The study group consisted of 58 patients with hyperthyroidism-induced persistent AF (mean age 57 +/- 2 years, 72% men) who had undergone successful electrical cardioversion. The AF recurrence rate was prospectively studied and compared with age- and gender-matched controls with persistent AF of nonthyroid origins. After a 24-month follow-up period, 34 patients (59%) had developed AF recurrence, significantly fewer than among controls (83%) (hazard ratio 0.64, 95% confidence interval 0.39 to 0.97, p = 0.04). Cox regression analysis showed that long AF duration was the only predictor of AF recurrence in patients with hyperthyroidism-induced persistent AF. In conclusion, hyperthyroidism-induced persistent AF carries a lower recurrence rate after conversion to sinus rhythm than non-hyperthyroidism-induced persistent AF, and early electrical cardioversion should be considered.

Hyperthyroidism-induced left ventricular diastolic dysfunction: implication in hyperthyroidism-related heart failure

Background  Heart failure occurs in 6% of hyperthyroid patients. Nonetheless, only half of those with hyperthyroidism‐related heart failure have impaired left ventricular (LV) systolic function. Thus, diastolic dysfunction may play an important role in the pathogenesis.

Prevalence and predictors of new-onset atrial fibrillation after elective surgery for colorectal cancer

There are only limited data on the prevalence and risk factors for postoperative atrial fibrillation (AF) after elective abdominal surgery. We retrospectively studied the clinical characteristics and hospital outcomes in 563 consecutive patients (mean age: 67 ± 13 years, 245 men) with colorectal cancer who underwent elective colectomy. The baseline clinical characteristics of patients who underwent open (OC) versus laparoscopic colectomy (LC) were similar. Postoperative AF developed in 25 patients (4.4%). Patients who developed postoperative AF were older (P = 0.017), had a higher prevalence of hypertension (P = 0.05), more major postoperative events (P = 0.02), an elevated neutrophil count on postoperative day (POD) 1 (P = 0.007), longer hospitalizations (P = 0.02), and were more likely to undergo OC (P = 0.067). In multiple regression analysis, independent predictors of postoperative AF were OC (odd ratio: 3.3, 95% confidence interval: 1.3–8.0, P = 0.008), and an elevated neutrophil count on POD 1 (odd ratio: 3.2, 95% confidence interval: 1.3–7.8, P = 0.01). The incidence of postoperative AF after elective colorectal cancer surgery was approximately 4%. Postoperative AF was more commonly observed in patients with OC versus LC and in those with elevated postoperative neutrophil counts.

Modified crush technique with double kissing balloon inflation (sleeve technique): A novel technique for coronary bifurcation lesions

We report a modified crush technique with double kissing balloon inflation (the sleeve technique) in an attempt to increase the success rate of final kissing balloon inflation, which has been shown to improve the angiographic outcomes of side branch in bifurcation lesions. A stent was advanced across the side branch with protrusion of 3–5 mm of proximal stent segment into the main vessel. At the same time, a size‐matched balloon with length long enough to cover the bifurcation as well as the protruding stent segment was placed in the main vessel. The side‐branch stent is deployed first, the wire and stent balloon are removed. This is followed by balloon inflation in main vessel at high pressure to crush the protruding stent segment against vessel wall. The side branch is then rewired, two balloons are advanced to the main vessel and side branch, and the bifurcation is kissed with balloons the first time. The side branch is now like a new sleeve. The balloon and wire of the side branch are removed. Another stent was positioned and then deployed in the main vessel. The side branch is rewired the second time, two balloons are advanced to the main vessel and side branch again, followed by final (second) kissing balloon inflation of the bifurcation. The sleeve technique has been employed in six consecutive patients with 100% success rate of final kissing balloon inflation. There was no major adverse cardiac events or stent thrombosis encountered within 30 days of percutaneous coronary intervention.

Stenting of coronary bifurcation lesions by using modified crush technique with double kissing balloon inflation (sleeve technique): Immediate procedure result and short‐term clinical outcomes

Background: Sleeve technique is a modified version of crush technique. It is specifically designed to increase the success rate of final kissing balloon inflation, which used to be a major limitation of the latter. Objectives: The aim of this study was to examine the feasibility, safety, and early clinical outcomes of sleeve technique in stenting different types (de novo, in‐stent restenotic or in‐stent bifurcation) of coronary bifurcation lesions at different locations. Methods: From August 2005 to May 2006, 41 consecutive patients with symptomatic, nonleft‐main coronary bifurcation stenoses of diameter narrowing ≥50% were treated with two‐stent strategy, using sleeve technique. Results: The mean age was 63.6 ± 11.6 years with male predominance (70.7%). High prevalence of diabetes mellitus (31.7%), total occlusion (22.0%), and multi‐vessel disease (65.9%) was observed in this cohort. Intravenous abciximab was given in 35 (85.4%) patients. Final kissing balloon inflation was successfully performed in all patients. The minimal luminal diameter in main vessel and side branch was increased from 0.97 ± 0.53 mm and 0.81 ± 0.45 mm to 2.76 ± 0.34 mm and 2.22 ± 0.35 mm, respectively. The mean procedure time was only 66.6 ± 24.6 min. There was one (2.4%) case of subacute stent thrombosis presented as non‐Q‐wave myocardial infarction at day 3 postprocedure. The resultant in‐hospital and 30‐day major adverse cardiac event rate were both 2.4%. Conclusions: Sleeve technique is a feasible and efficient approach in stenting of coronary bifurcation stenoses.

Low molecular weight heparin versus unfractionated heparin for thromboprophylaxis in patients with acute atrial fibrillation: A randomized control trial

While long-term anticoagulation prevents ischemic stroke in high-risk patients with atrial fibrillation (AF), the optimal initial anti-thrombotic regime in acute AF is less well defined. We randomized 96 patients with new onset acute AF in an emergency admission ward to receive (1) once-daily preparation of low molecular weight heparin (LMWH), tinzaparin or (2) conventional intravenous unfractionated heparin (target APTT 50–70 s). 5 patients in unfractionated heparin group compared with no patients in LMWH group (0%, P = 0.04) developed ischemic stroke/transient ischemic attack during the first 48 h. An initial subcutaneous LMWH was safe and effective in ischemic stroke prevention in patients with acute AF.