Transcatheter aortic valve implantation in acute decompensated aortic stenosis.

OBJECTIVES: To assess the safety and efficacy of first-line transcatheter aortic valve implantation (TAVI) in patients presenting with acute decompensated aortic stenosis (ADAS). BACKGROUND: ADAS is common and is often treated medically or using balloon aortic valvuloplasty in the first instance. This temporizing measure results in suboptimal outcomes. In the current era, TAVI provides an alternative option. METHODS: Consecutive patients who had either a TAVI for ADAS or electively were included in the study. The primary outcome was procedural and 30-day mortality and hospital length of stay (LOS). Secondary outcomes included 1-year mortality and procedural complications. RESULTS: Of note, 893 patients (mean age 83 ± 7, 50.5% male) underwent TAVI (19% ADAS, 81% elective). ADAS patients were more unwell with worse echocardiographic parameters than elective patients. ADAS patients of 55.9% were known to have significant aortic stenosis prior to their decompensation. Procedural mortality was not different between the ADAS and elective cohorts (1.2 vs. 0.7%; p = .62). The ADAS cohort had a higher 30-day mortality (5.3 vs. 1.1%; p = .002) and longer LOS (31.9 ± 20.7 days vs. 6.1 ± 6.5 days; p < .001). Multivariate analysis identified acute kidney injury and ADAS as significant predictors of 30-day mortality. CONCLUSIONS: TAVI for ADAS is safe and effective with procedural outcomes similar to elective patients. However, compared to elective patients, they have worse physiological baseline features, poorer prognosis at 30 days, and longer hospital admissions. Majority of patients who presented with ADAS were known to have AS prior to admission.

Mechanisms of Myocardial Ischemia in Hypertrophic Cardiomyopathy: Insights From Wave Intensity Analysis and Magnetic Resonance.

BACKGROUND: Angina is common in hypertrophic cardiomyopathy (HCM) and is associated with abnormal myocardial perfusion. Wave intensity analysis improves the understanding of the mechanics of myocardial ischemia. OBJECTIVES: Wave intensity analysis was used to describe the mechanisms underlying perfusion abnormalities in patients with HCM. METHODS: Simultaneous pressure and flow were measured in the proximal left anterior descending artery in 33 patients with HCM and 20 control patients at rest and during hyperemia, allowing calculation of wave intensity. Patients also underwent quantitative first-pass perfusion cardiac magnetic resonance to measure myocardial perfusion reserve. RESULTS: Patients with HCM had a lower coronary flow reserve than control subjects (1.9 ± 0.8 vs. 2.7 ± 0.9; p = 0.01). Coronary hemodynamics in HCM were characterized by a very large backward compression wave during systole (38 ± 11% vs. 21 ± 6%; p < 0.001) and a proportionately smaller backward expansion wave (27% ± 8% vs. 33 ± 6%; p = 0.006) compared with control subjects. Patients with severe left ventricular outflow tract obstruction had a bisferiens pressure waveform resulting in an additional proximally originating deceleration wave during systole. The proportion of waves acting to accelerate coronary flow increased with hyperemia, and the magnitude of change was proportional to the myocardial perfusion reserve (rho = 0.53; p < 0.01). CONCLUSIONS: Coronary flow in patients with HCM is deranged. Distally, compressive deformation of intramyocardial blood vessels during systole results in an abnormally large backward compression wave, whereas proximally, severe left ventricular outflow tract obstruction is associated with an additional deceleration wave. Perfusion abnormalities in HCM are not simply a consequence of supply/demand mismatch or remodeling of the intramyocardial blood vessels; they represent a dynamic interaction with the mechanics of myocardial ischemia that may be amenable to treatment.

Arterial pulse wave dynamics after percutaneous aortic valve replacement: fall in coronary diastolic suction with increasing heart rate as a basis for angina symptoms in aortic stenosis.

BACKGROUND: Aortic stenosis causes angina despite unobstructed arteries. Measurement of conventional coronary hemodynamic parameters in patients undergoing valvular surgery has failed to explain these symptoms. With the advent of percutaneous aortic valve replacement (PAVR) and developments in coronary pulse wave analysis, it is now possible to instantaneously abolish the valvular stenosis and to measure the resulting changes in waves that direct coronary flow. METHODS AND RESULTS: Intracoronary pressure and flow velocity were measured immediately before and after PAVR in 11 patients with unobstructed coronary arteries. Using coronary pulse wave analysis, we calculated the intracoronary diastolic suction wave (the principal accelerator of coronary blood flow). To test physiological reserve to increased myocardial demand, we measured at resting heart rate and during pacing at 90 and 120 bpm. Before PAVR, the basal myocardial suction wave intensity was 1.9±0.3×10(-5) W · m(-2) · s(-2), and this increased in magnitude with increasing severity of aortic stenosis (r=0.59, P=0.05). This wave decreased markedly with increasing heart rate (ß coefficient=-0.16×10(-4) W · m(-2) · s(-2); P<0.001). After PAVR, despite a fall in basal suction wave (1.9±0.3 versus 1.1±0.1×10(-5) W · m(-2) · s(-2); P=0.02), there was an immediate improvement in coronary physiological reserve with increasing heart rate (ß coefficient=0.9×10(-3) W · m(-2) · s(-2); P=0.014). CONCLUSIONS: In aortic stenosis, the coronary physiological reserve is impaired. Instead of increasing when heart rate rises, the coronary diastolic suction wave decreases. Immediately after PAVR, physiological reserve returns to a normal positive pattern. This may explain how aortic stenosis can induce anginal symptoms and their prompt relief after PAVR. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01118442.