Microvascular angina in a patient with aortic stenosis

Very severe aortic stenosis masquerading as acute coronary syndrome

Severe aortic stenosis (AS) may rarely present like acute coronary syndrome with increased cardiac biomarker despite having normal coronaries. Here we describe a case of very severe AS, who presented with exertional and rest angina and a high level of TnI. Angiography revealed normal coronaries. Echocardiography showed very severe AS with peak velocity of 5.08 m/s and maximum and mean gradient of 103 and 54 mm Hg, respectively. The patient subsequently underwent aortic valve replacement (AVR) successfully. Subendocardial ischaemia may occur in patients with severe AS during haemodynamic stress, even in the setting of normal unobstructed coronaries due to supply-demand mismatch. Subsequent degeneration and death of the cardiac myocytes cause cTnI elevation, which anticipates the start of the clinical downhill course in severe AS. Our case highlights the importance of thorough physical examination and early use of echocardiography in patients with angina to detect the presence of severe AS.

[Functional vascular alterations associated with aortic valve stenosis]

Degenerative changes, atherosclerotic process and calcification of valvular leaflets are mostly responsible for valvular aortic valve stenosis, but congenital bicuspid aortic valve and rheumatic fever in history are also known predisposing factors. Aortic valve stenosis is frequently associated with different functional vascular alterations. The aim of this review is to demonstrate these vascular alterations evaluated by non-invasive methods and underlying physiologic and pathophysiologic processes.

Is the coronary flow velocity reserve improvement after aortic valve replacement for aortic stenosis transient? Results of a 3-year follow-up

The coronary flow velocity reserve (CFR) is decreased in patients with aortic valve stenosis (AS). The aim of the present prospective study was to examine the CFR in AS patients with normal epicardial coronary arteries during a 3-year follow-up of aortic valve replacement (AVR). A total of 30 AS patients (17 women and 13 men) were enrolled in this prospective follow-up study; they all had a normal coronary angiogram and underwent dipyridamole stress transesophageal echocardiography (STEE) for CFR measurement before AVR. Nine of them participated in this 3-year follow-up study, and all patients were examined 16 months and 3 years after AVR by STEE. The CFR of AS patients was decreased before AVR. Different extents of diastolic coronary flow velocity reduction (resting and posthyperaemic) were observed resulting in a significant CFR improvement, despite the low number of patients during the 16-month follow-up. A further posthyperaemic flow velocity reduction was demonstrated after the 3-year follow-up, resulting in a significant CFR impairment. The CFR decreased in 5 cases, but remained practically unchanged in 3 after the first CFR measurement; only the CFR of 1 patient improved minimally. The main finding of the current study is that the CFR improvement 16 months after AVR, which paralleled the regression of the left ventricular hypertrophy, was found to be transient. Coronary flow velocity reserve impairment was demonstrated after the long-term (3-year) follow-up in most of the patients, which could not be explained by extravascular compressive forces.

Myocardial infarction in a patient with severe aortic stenosis and normal coronary arteriograms: involvement of the circumferential subendocardial wall of the left ventricle

A case of severe aortic stenosis with normal coronary arteriograms was associated with myocardial infarction involving the circumferential subendocardial wall of the left ventricle. The infarct was caused solely by the severe aortic stenosis and resulted from the extreme disparity between myocardial oxygen supply and demand.

Evaluation by Contrast-Enhanced Electron Beam Computed Tomography of Myocardial Perfusion and Tissue Characteristics in Congenital Aortic Stenosis

The evaluation of myocardial perfusion and tissue characteristics gives useful information regarding the indication for surgery. In the present study, two-phase contrast enhanced electron beam computed tomography (EBT) was used to quantitatively examine myocardial perfusion and the tissue characteristics of the left ventricular (LV) myocardium in congenital aortic stenosis (AS). The AS group comprised 15 patients and the control group had 14 non-AS patients. Myocardial ischemia and tissue characteristics were evaluated by the ratio of the incremental CT number of the myocardium (M) and the lumen (L) of the LV (M/L) in, the early phase with and without dipyridamole (Dp) loading and in the late phase after enhancement (respectively). In a comparison between the AS group and the controls, mean early M/Ls were significantly lower in the AS group than in the controls (20+/-5% vs 37+/-10%, p<0.01) and mean late M/Ls in the AS group were also significantly lower (47+/-11% vs 62+/-13%, p<0.01). In the AS patients, early M/Ls in the subendocardial and apical regions were especially lower than those of other segments, but the late M/Ls in these segments were inversely higher than those of other segments. These results suggest 2 things: (1) the existence of latent LV myocardial ischemia in AS patients, which is probably because of a hypertrophied LV wall, in turn caused by afterload, and (2) the presence of more myocardial ischemia and interstitial fibrosis in the subendocardial and apical regions of the AS heart. Using Dp loading for the AS patients increased the clarity of the contrast images. Contrast-enhanced EBT is useful for evaluating myocardial characteristics and perfusion in AS, and gives new insight into the LV wall characteristics in AS, as well as an indication for surgical correction of congenital AS.

Clinical characteristics and follow-up in patients with microvascular angina

Arteriosclerosis of the small arteries is one of the main causes of microvascular angina, and although some reports have shown favorable prognoses, there is progressive reduction in left ventricular function. The present study evaluated the prognosis of microvascular angina in 86 Japanese patients (51 women, 35 men; average age, 59+/-9 years) who had ischemic ST segment depression, normal coronary angiograms and small artery sclerosis confirmed by endomyocardial biopsies. The mean follow-up period was 7.2+/-3.4 years. Questionnaires regarding their symptoms, cardiac medication, and new events were sent to all patients. Eighty-five patients (98.9%) were still alive at the end of the follow-up period. Chest pain remained in 35.3%; the degree of pain was unchanged in 18.8%, and had lessened in 11.8%. None of the patients died of cardiac events or suffered from a myocardial infarction. At the end of the follow-up period, calcium antagonist was used in 63.5% of patients. Seventeen patients (20.0%) were free of antianginal medication. The prognosis of microvascular angina diagnosed by strict criteria was favorable.