Background A relevant proportion of patients with suspected coronary artery disease undergo invasive coronary angiography showing normal or nonobstructive coronary arteries. However, the prevalence ...of coronary microvascular disease (CMD) and coronary spasm in patients with nonobstructive coronary artery disease remains to be determined. The objective of this study was to determine the prevalence of coronary CMD and coronary vasospastic angina in patients with no obstructive coronary artery disease. Methods and Results A systematic review and meta-analysis of studies assessing the prevalence of CMD and vasospastic angina in patients with no obstructive coronary artery disease was performed. Random-effects models were used to determine the prevalence of these 2 disease entities. Fifty-six studies comprising 14 427 patients were included. The pooled prevalence of CMD was 0.41 (95% CI, 0.36-0.47), epicardial vasospasm 0.40 (95% CI, 0.34-0.46) and microvascular spasm 24% (95% CI, 0.21-0.28). The prevalence of combined CMD and vasospastic angina was 0.23 (95% CI, 0.17-0.31). Female patients had a higher risk of presenting with CMD compared with male patients (risk ratio, 1.45 95% CI, 1.11-1.90). CMD prevalence was similar when assessed using noninvasive or invasive diagnostic methods. Conclusions In patients with no obstructive coronary artery disease, approximately half of the cases were reported to have CMD and/or coronary spasm. CMD was more prevalent among female patients. Greater awareness among physicians of ischemia with no obstructive coronary arteries is urgently needed for accurate diagnosis and patient-tailored management.
Aim
Microvascular resistance reserve (MRR) as derived from continuous intracoronary thermodilution specifically quantifies microvasculature function. As originally described, the technique ...necessitates reinstrumentation of the artery and manual reprogramming of the infusion pump when performing resting and hyperemic measurements. To simplify and to render this procedure operator‐independent, we developed a fully automated method. The aim of the present study is to validate the automated procedure against the originally described one.
Methods and Results
For the automated procedure, an infusion pump was preprogrammed to allow paired resting‐hyperemic thermodilution assessment without interruption. To validate the accuracy of this new approach, 20 automated measurements were compared to those obtained in the same vessels with conventional paired resting‐hyperemic thermodilution measurements (i.e., with a sensor pullback at each infusion rate and manual reprogramming of the infusion pump).
A close correlation between the conventional and the automated measuring technique was found for resting flow (Qrest: r = 0.89, mean bias = 2.52; SD = 15.47), hyperemic flow (Qhyper: r = 0.88, mean bias = −2.65; SD = 27.96), resting microvascular resistance (Rμ‐rest: r = 0.90, mean bias = 52.14; SD = 228.29), hyperemic microvascular resistance Rμ‐hyper: r = 0.92, mean bias = 12.95; SD = 57.80), and MRR (MRR: r = 0.89, mean bias = 0.04, SD = 0.59).
Procedural time was significantly shorter with the automated method (5′25″ ± 1′23″ vs. 4′36″ ± 0′33″, p = 0.013).
Conclusion
Continuous intracoronary thermodilution‐derived measurements of absolute flow, absolute resistance, and MRR can be fully automated. This further shortens and simplifies the procedure when performing paired resting‐hyperemic measurements.
Graphical Abstract
Graphical Abstract
Is Takutsubo syndrome (TTS) just the tip of the iceberg? Coronary microvascular dysfunction (CMD) is a prevalent underlying factor in numerous cardiovascular ...diseases, including ischaemic heart disease, microvascular angina, heart failure with preserved ejection fraction, and TTS. While microvascular angina may represent the most significant clinically evident manifestation of CMD, an acute disruption of dysfuntional mechanisms in an impaired coronary microcirculation—potentially due to external triggers (indicated by the lightning bolt) such as severe stress—provides a suitable explanation for the pathophysiology underlying TTS. Consequently, TTS can be classified as an acute microvascular syndrome.
Background. To validate a simplified invasive method for the calculation of the index of microvascular resistance (IMR). Methods. This is a prospective, single-center study of patients with chronic ...coronary syndromes presenting with nonobstructive coronary artery disease. IMR was obtained using both intravenous (IV) adenosine and intracoronary (IC) papaverine. Each IMR measurement was obtained in duplicate. The primary objective was the agreement between IMR acquired using adenosine and papaverine. Secondary objectives include reproducibility of IMR and time required for the IMR measurement. Results. One hundred and sixteen IMR measurements were performed in 29 patients. The mean age was 68.8 ± 7.24 years, and 27.6% was diabetics. IMR values were similar between papaverine and adenosine (17.7 ± 7.26 and 20.1 ± 8.6, p=0.25; Passing-Bablok coefficient A 0.58, 95% CI −2.42 to 3.53; coefficient B 0.90, 95% CI −0.74 to 1.07). The reproducibility of IMR was excellent with both adenosine and papaverine (ICC 0.78, 95% CI 0.63 to 0.88 and ICC 0.93, 95% CI 0.87 to 0.97). The time needed for microvascular assessment was significantly shortened by the use of IC papaverine (3.23 (2.84, 3.78) mins vs. 5.48 (4.94, 7.09) mins, p<0.0001). Conclusion. IMR can be reliably measured using IC papaverine with similar results compared to intravenous infusion of adenosine with increased reproducibility and reduced procedural time. This approach simplifies the invasive assessment of the coronary microcirculation in the catheterization laboratory.
Coronary microvascular dysfunction (CMD) is an early feature of diabetic cardiomyopathy, which usually precedes the onset of diastolic and systolic dysfunction. Continuous intracoronary ...thermodilution allows an accurate and reproducible assessment of absolute coronary blood flow and microvascular resistance thus allowing the evaluation of coronary flow reserve (CFR) and Microvascular Resistance Reserve (MRR), a novel index specific for microvascular function, which is independent from the myocardial mass. In the present study we compared absolute coronary flow and resistance, CFR and MRR assessed by continuous intracoronary thermodilution in diabetic vs. non-diabetic patients. Left atrial reservoir strain (LASr), an early marker of diastolic dysfunction was compared between the two groups.
In this observational retrospective study, 108 patients with suspected angina and non-obstructive coronary artery disease (NOCAD) consecutively undergoing elective coronary angiography (CAG) from September 2018 to June 2021 were enrolled. The invasive functional assessment of microvascular function was performed in the left anterior descending artery (LAD) with intracoronary continuous thermodilution. Patients were classified according to the presence of DM. Absolute resting and hyperemic coronary blood flow (in mL/min) and resistance (in WU) were compared between the two cohorts. FFR was measured to assess coronary epicardial lesions, while CFR and MRR were calculated to assess microvascular function. LAS, assessed by speckle tracking echocardiography, was used to detect early myocardial structural changes potentially associated with microvascular dysfunction.
The median FFR value was 0.83 0.79-0.87 without any significant difference between the two groups. Absolute resting and hyperemic flow in the left anterior descending coronary were similar between diabetic and non-diabetic patients. Similarly, resting and hyperemic resistances did not change significantly between the two groups. In the DM cohort the CFR and MRR were significantly lower compared to the control group (CFR = 2.38 ± 0.61 and 2.88 ± 0.82; MRR = 2.79 ± 0.87 and 3.48 ± 1.02 for diabetic and non-diabetic patients respectively, p < 0.05 for both). Likewise, diabetic patients had a significantly lower reservoir, contractile and conductive LAS (all
< 0.05).
Compared with non-diabetic patients, CFR and MRR were lower in patients with DM and non-obstructive epicardial coronary arteries, while both resting and hyperemic coronary flow and resistance were similar. LASr was lower in diabetic patients, confirming the presence of a subclinical diastolic dysfunction associated to the microcirculatory impairment. Continuous intracoronary thermodilution-derived indexes provide a reliable and operator-independent assessment of coronary macro- and microvasculature and might potentially facilitate widespread clinical adoption of invasive physiologic assessment of suspected microvascular disease.
Background Deferring revascularization in patients with nonsignificant stenoses based on fractional flow reserve (FFR) is associated with favorable clinical outcomes up to 15 years. Whether this ...holds true in patients with reduced left ventricular ejection fraction is unclear. We aimed to investigate whether FFR provides adjunctive clinical benefit compared with coronary angiography in deferring revascularization of patients with intermediate coronary stenoses and reduced left ventricular ejection fraction. Methods and Results Consecutive patients with reduced left ventricular ejection fraction (≤50%) undergoing coronary angiography between 2002 and 2010 were screened. We included patients with at least 1 intermediate coronary stenosis (diameter stenosis ≥40%) in whom revascularization was deferred based either on angiography plus FFR (FFR guided) or angiography alone (angiography guided). The primary end point was the cumulative incidence of all‐cause death at 10 years. The secondary end point (incidence of major adverse cardiovascular and cerebrovascular events) was a composite of all‐cause death, myocardial infarction, any revascularization, and stroke. A total of 840 patients were included (206 in the FFR‐guided group and 634 in the angiography‐guided group). Median follow‐up was 7 years (interquartile range, 3.22–11.08 years). After 1:1 propensity‐score matching, baseline characteristics between the 2 groups were similar. All‐cause death was significantly lower in the FFR‐guided group compared with the angiography‐guided group (94 45.6% versus 119 57.8%; hazard ratio HR, 0.65 95% CI, 0.49–0.85; P <0.01). The rate of major adverse cardiovascular and cerebrovascular events was lower in the FFR‐guided group (123 59.7% versus 139 67.5%; HR, 0.75 95% CI, 0.59–0.95; P =0.02). Conclusions In patients with reduced left ventricular ejection fraction, deferring revascularization of intermediate coronary stenoses based on FFR is associated with a lower incidence of death and major adverse cardiovascular and cerebrovascular events at 10 years.
To evaluate the feasibility and accuracy of quantification of calcified coronary stenoses using virtual non-calcium (VNCa) images in coronary CT angiography (CCTA) with photon-counting detector (PCD) ...CT compared with quantitative coronary angiography (QCA).
This retrospective, institutional-review board approved study included consecutive patients with calcified coronary artery plaques undergoing CCTA with PCD-CT and invasive coronary angiography between July and December 2022. Virtual monoenergetic images (VMI) and VNCa images were reconstructed. Diameter stenoses were quantified on VMI and VNCa images by two readers. 3D-QCA served as the standard of reference. Measurements were compared using Bland-Altman analyses, Wilcoxon tests, and intraclass correlation coefficients (ICC).
Thirty patients mean age, 64 years ± 8 (standard deviation); 26 men with 81 coronary stenoses from calcified plaques were included. Ten of the 81 stenoses (12%) had to be excluded because of erroneous plaque subtraction on VNCa images. Median diameter stenosis determined on 3D-QCA was 22% (interquartile range, 11%-35%; total range, 4%-88%). As compared with 3D-QCA, VMI overestimated diameter stenoses (mean differences -10%,
< .001, ICC: .87 and -7%,
< .001, ICC: .84 for reader 1 and 2, respectively), whereas VNCa images showed similar diameter stenoses (mean differences 0%,
= .68, ICC: .94 and 1%,
= .07, ICC: .93 for reader 1 and 2, respectively).
First experience in mainly minimal to moderate stenoses suggests that virtual calcium removal in CCTA with PCD-CT, when feasible, has the potential to improve the quantification of calcified stenoses.
Background: Calcified coronary lesions represent technical challenges during percutaneous
coronary intervention and are associated with a high frequency of restenosis and target lesion
...revascularization. Rotational atherectomy has been shown to increase procedural success in severely
calcified lesions, facilitate stent delivery in undilatable lesions and ensure complete stent expansion.
However, rotational atherectomy in ST-elevation Myocardial Infarction (STEMI) is traditionally
avoided given the concern for slow or no reflow and considered a contraindication in lesions
with a visible thrombus by its manufacturer (Rotablator, Boston Scientific).
Conclusion: This case demonstrates the successful use of rotational atherectomy to facilitate dilation
and revascularization of a heavily calcified culprit lesions in a patient with acute anterior
STEMI with ongoing chest pain.
Myocardial bridging (MB) is the most frequent congenital coronary anomaly characterized by a segment of an epicardial coronary artery that passes through the myocardium. MB is an important cause of ...myocardial ischemia and is also emerging as a possible cause of myocardial infarction with non-obstructed coronary arteries (MINOCA). There are multiple mechanisms underlying MINOCA in patients with MB (i.e., MB-mediated increased risk of epicardial or microvascular coronary spasm, atherosclerotic plaque disruption and spontaneous coronary artery dissection). The identification of the exact pathogenetic mechanism is crucial in order to establish a patient-tailored therapy. This review provides the most up-to-date evidence regarding the pathophysiology of MINOCA in patients with MB. Moreover, it focuses on the available diagnostic tools that could be implemented at the time of coronary angiography to achieve a pathophysiologic diagnosis. Finally, it focuses on the therapeutic implications associated with the different pathogenetic mechanisms of MINOCA in patients with MB.
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