Kotaro Numaguchi

Clinical impact of coronary artery spasm in patients with no significant coronary stenosis in acute coronary syndromes

BACKGROUND AND OBJECTIVE To clarify the clinical features of coronary artery spasm (CAS) with no significant coronary stenosis in patients with suspected acute coronary syndrome (ACS) in real practice. METHODS This is a retrospective observational study of patients with suspected ACS (n=645) based on symptoms, electrocardiographic changes, and/or positive cardiac biomarkers and vasospastic angina (VSA, n=90). ACS patients were divided into two groups: (1) organic ACS (n=515), culprit lesion ≥75% coronary stenosis with/without thrombosis; (2) spastic ACS (n=70), coronary stenosis <75%, either with positive acetylcholine (ACh) test (n=51) or without ACh test but verified spontaneous spasm (n=19). The study compared clinical characteristics among organic ACS, spastic ACS, and VSA. RESULTS One hundred and thirty suspected ACS patients had a coronary organic stenosis <75% (130/645, 20%). Seventy of those patients (70/130, 54%) were confirmed to have CAS, and these accounted for 11% of all ACS patients (70/645). The rate of cigarette smoking was highest in the spastic ACS. No spastic ACS patients died during their hospital stay or after discharge, whereas acute myocardial infarction occurred in 19%, aborted sudden cardiac death in 6%, multivessel spasm was provoked in 78%, and diffuse spasm was more frequently provoked than in the VSA group (82% vs. 62%). CONCLUSIONS CAS is not a rare cause of ACS. Although the prognosis of spastic ACS is good, there are occasional critical cases. An initial differential diagnosis including an ACh test is thus important to decide the treatment strategy of ACS.

Gender differences in factors influencing electrocardiographic findings of left ventricular hypertrophy in severe aortic stenosis

We investigated gender differences in factors influencing the electrocardiographic (ECG) findings of left ventricular hypertrophy (LVH) in patients with severe aortic stenosis (AS). The functional and geometric responses of the left ventricle to chronic pressure overload, such as hypertension and AS, have been reported to be different between men and women. However, gender differences in the factors influencing the ECG findings of LVH in pressure overload remain unknown. We conducted a retrospective observational study in consecutive patients with severe AS (aortic valve area (AVA) assessed by cardiac catheterization <1.0 cm2) without concomitant significant aortic regurgitation, mitral stenosis and/or regurgitation, conduction disturbance, or myocardial infarction (n = 35 males, 68 females). The ECG criteria were classified into three categories: (1) high voltage by the Sokolow–Lyon index associated with ST-T wave changes (with no digitalis therapy); (2) high voltage alone; and (3) normal. Groups 1 and 2 were defined as LVH on ECG. We compared the ECG findings in relation to the AS severity between genders. Women were older, but there were no significant differences in the prevalence of hypertension, AVA index (AVAI), mean pressure gradient or peak velocity across the AV, LV mass index (LVMI) derived from echocardiography or the distribution of ECG categories between genders. A multiple logistic regression analysis including age, gender, hypertension, AVAI, mean pressure gradient, and LVMI revealed that the LVMI (P = 0.001) and AVAI (P = 0.0434) were significantly related to the distribution of ECG categories. LVMI significantly predicted LVH on ECG in both genders, but AVAI was a predictive factor in only women. ECG LVH in patients with severe AS may be mainly reflected by LVMI in men and by both LVMI and AVAI in women. Factors other than AVA, such as end-stage disease and/or complicating factors such as hypertension, may underlie the observed differences in ECG findings of LVH between men and women.

A kinked aortic tube graft after aortic root replacement causes heart failure: usefulness of the right parasternal approach on echocardiography

A 69-year-old male with a history of aortic root replacement and aortic valve replacement for acute type A aortic dissection 11 years previously was referred with a 1-month history of exertional dyspnea. He had a grade 4 ejection systolic murmur that was best heard at the second intercostal level of the right sternal border. On echocardiogram, the mechanical aortic valve was not obstructed, and the opening of the pulmonary valve was preserved. Pulmonary hypertension was mild because the pressure gradient estimated by the velocity of tricuspid regurgitation was 31 mmHg. We then observed the ascending aorta in the right recumbent position, with the transducer to the right of the sternum at the second intercostal space. An aortic tube graft in the ascending aorta was kinked and accelerated flow was found (Fig. 1a). Its peak velocity was over 4 m/s (Fig. 1b). Contrast-enhanced CT scan generated a similar image as echocardiogram did (Fig. 1c, d). In the operative findings, we found that the previous aortic graft was severely kinked and it was probably caused by inappropriate length following graft–graft anastomosis at the previous surgery. In this operation, a fan-shaped straight graft was prepared and implanted to prevent a kink in the prosthetic graft. The postoperative course was satisfactory and uncomplicated. The patient described marked relief of exertional dyspnea and improved exercise tolerance.