https://doi.org/10.53453/ms.2025.11.5
Coronary sinus reducer for the treatment of refractory angina: a
literature review
Domas Kazokas
1
, Linda Valiulytė
2
, Algirdas Valiulis
3
, Saulė Kraujutaitytė
1
1
Lithuanian University of Health Sciences, Medical Academy, Faculty of Medicine, Kaunas, Lithuania
2
Abromiškės Rehabilitation Hospital, Diagnostic Department, Abromiškės, Lithuania
3
Vilnius University, Faculty of Medicine, Institute of Health Sciences, Vilnius, Lithuania
Abstract
Background. Refractory angina remains an important health issue despite improvements in coronary artery
disease diagnosis and treatment, and its incidence is expected to grow. Although patients with refractory angina
exhibit a mortality rate comparable to that of individuals with asymptomatic stable angina, the quality of life is
worse and associated healthcare expenditure is higher. After having exhausted all treatment options, coronary
sinus reducer (CSR) has recently gained more attention as a non – pharmacological treatment of refractory angina.
Aim. To summarize the current knowledge about CSR for the treatment of refractory angina, its mechanism of
action, efficacy, safety and cost-effectiveness.
Materials and methods. A comprehensive literature search was performed on PubMed database using the
keywords “coronary sinus reduction” AND “refractory angina”, focusing on articles published in English in the
last 5 years.
Results. Implantation of the CSR creates backward pressure in the coronary venous circulation resulting in a
redistribution of flow from the subepicardial to the ischaemic subendocardial region. This translates into sustained
angina reduction as demonstrated by a significant improvement in Canadian Cardiovascular Society angina class,
quality of life, mainly as assessed by the Seattle Angina Questionnaire, increased exercise tolerance as assessed
by the 6-minute walk test and improved left ventricular systolic function. Under proper selection, CSR could also
be of benefit to patients with right coronary artery disease. The most common complication is haematoma at the
vascular access site. Cost-effectiveness is achieved within 2 years.
Conclusions. CSR is an efficient, safe and cost-effective treatment of refractory angina.
Keywords: coronary sinus reducer, coronary sinus reduction, refractory angina, non-pharmacological treatment.
Journal of Medical Sciences. 8 Nov, 2025 - Volume 13 | Issue 5. Electronic - ISSN: 2345-0592
Medical Sciences 2025 Vol. 13 (5), p. 48-61, https://doi.org/10.53453/ms.2025.11.5
48
1. Introduction
Refractory angina refers to ≥3 months lasting
symptoms of angina due to known reversible
ischaemia in the presence of obstructive
coronary artery disease (CAD), which cannot be
controlled by escalating medical therapy
(including second- and third-line
pharmacological agents), bypass grafting, or
stenting including percutaneous coronary
intervention (PCI) of chronic total coronary
occlusion; or due to angina / ischaemia with non-
obstructive coronary arteries (ANOCA/INOCA)
[1]. Refractory angina remains an important
issue despite improvements in CAD diagnosis
and treatment – it accounts for 30 000 – 50 000
new cases/year in Europe, making up 5-10% of
patients with stable angina [2]. The incidence of
refractory angina is expected to grow due to
population ageing, increasing complexity of
CAD and the presence of multiple comorbidities
– all factors limiting the spectrum of therapeutic
options [3]. Patients with refractory angina
exhibit a mortality rate comparable to that of
individuals with asymptomatic stable angina,
however the quality of life is worse, and
healthcare expenditure associated with
refractory angina is higher. After having
exhausted all options for medical therapy and
mechanical revascularization, 2024 European
Society of Cardiology Guidelines on chronic
coronary syndromes suggest coronary sinus
reducer (CSR) as one of the non-
pharmacological treatments (class IIb
recommendation, level of evidence B) [1].
During this minimally invasive procedure an
hourglass-shaped stainless-steel mesh is
implanted percutaneously via right internal
jugular vein in the coronary sinus, thus
narrowing its lumen. This procedure has recently
gained more attention as a potentially effective,
safe and accessible option for the treatment of
refractory angina [3]. This literature review aims
to summarize current knowledge about CSR for
the treatment of refractory angina, its mechanism
of action, efficacy, safety and cost-effectiveness.
2. Materials and methods
A comprehensive literature search was
conducted using PubMed database. Articles
published in the last 5 years in English were
selected for the analysis. Case reports were
excluded. The following keywords were used:
“coronary sinus reduction” AND “refractory
angina”.
3. Results
3.1. Mechanism of action
In a healthy heart, exercise induces sympathetic-
mediated vasoconstriction of the subepicardial
vessels, thus directing more blood flow to the
subendocardial layer. With obstructive
epicardial coronary disease or microvascular
disease, these regulatory mechanisms are
compromised: the perfusion is no longer
redistributed to the subendocardial layer leading
to ischaemia of this region, which reduces
contractility; reduced contractility increases left
ventricular end-diastolic pressure thus
compressing subendocardial coronary vessels
and further reducing the perfusion of
subendocardial layer. Implantation of coronary
sinus narrowing device increases venous
pressure in the coronary circulation. Created
backward pressure in coronary venules,
capillaries and arterioles increases cross-
sectional area of these vessels, significantly
reducing the resistance in the vascular bed of
subendocardial layer. This results in a
redistribution of flow from the subepicardial to
the ischaemic subendocardial region, thus
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49
bringing the ratio between subepicardial
and subendocardial perfusion closer to that
observed in physiological conditions [2, 3]. In
silico study shows that the mechanism of
coronary sinus reducer depends on the severity
of coronary stenosis: in the case of moderate
coronary stenosis, an increase in capillary transit
time is the key mechanism, allowing more time
for myocardial oxygenation; with severe
coronary stenosis, redistribution of blood from
nonischaemic to ischaemic regions
predominates [4]. The imaging study using
rubidium-82 positron emission tomography
supports redistribution of myocardial blood flow
from well perfused to hypoperfused myocardium
under stress conditions in both the left and right
coronary artery distributions [5]. Similar results
were demonstrated by quantitative perfusion
cardiovascular magnetic resonance study [6].
3.2. Efficacy
Generally, studies show a significant reduction
in angina symptoms and number of antianginal
drugs, improved quality of life, increased
exercise tolerance after the implantation of CSR.
A total of 69,8 – 90,9% of patients improved by
at least 1 Canadian Cardiovascular Society
(CCS) angina class; 24,1 – 50,9% of patients
improved by at least 2 CCS classes [7–14]. Some
patients improved by 3 CCS classes and some
even became asymptomatic [8, 10]. The
observed variability in the improvement
proportions between studies could be partly
explained by differences in sample size and the
diversity of study design. Patients after CSR
implantation were more likely to have a lower
number of daily episodes of angina with odds
ratio (OR) of 1,40. Angina reduction with CSR
developed gradually over time (an effect
detectable at 10 weeks), in contrast to
percutaneous coronary intervention, where
angina reduction is immediate [15]. The
proportion of non-responders in the included
studies ranged from 15,8% to 25,0% of patients,
which is within the range of previously reported
rates in older literature [9]. A modest reduction
in the number of anti-anginal drugs was reported
[8, 9]. Studies show an improvement in Quality
of Life (QoL), mainly as assessed by the Seattle
Angina Questionnaire (SAQ); the majority of
studies show an improvement in all domains of
the SAQ [8, 9, 11–15]. An increase in exercise
tolerance, as assessed by the 6-minute walk test
(6-MWT), was observed and ranged from
10,45% to 36,07% increase in distance walked,
with a tendency for smaller increases with longer
follow-up [11–14]. CSR also improved left
ventricular (LV) function by increasing ejection
fraction (EF); this was more pronounced in
patients with baseline EF < 50%, resulting in an
11,3% increase compared with only an 3,8%
increase in patients with baseline EF > 50%; a
significant improvement of global
circumferential and global longitudinal strain
was observed; one study showed a reduction in
LV volumes, while the other found no significant
changes [10, 11]. Although it was previously
postulated that the increased venous pressure
induced by CSR implantation could cause
interstitial oedema with subsequent increase in
myocardial stiffness, no detrimental effects on
microstructural remodelling and associated
diastolic function were found [11]. The duration
of follow-up in the included studies ranged from
3 months to 3 years. At 3-year follow-up, CSR
was still effective, demonstrating sustainability
of performance [12].
It was generally believed that CSR would not be
effective in patients with isolated right coronary
artery (RCA) disease due to the cardiac venous
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50
anatomy: the inferior and inferoseptal LV wall
usually drains to the proximal coronary sinus,
whereas CSR is implanted more distally and
therefore has no means of generating backward
pressure [3, 16]. This group of patients has
traditionally been excluded from CSR studies.
However, patients with chronic total occlusion
(CTO) of the RCA differ from patients with non-
occlusive RCA disease by the presence of a
developed collateral network, mostly originating
from the left anterior descending (LAD) and
circumflex (LCX) coronary arteries, thus
creating a reason to speculate that even patients
with CTO RCA disease could benefit from CSR.
Mrak et al. evaluated the efficacy of CSR
implantation in refractory angina patients with
CTO RCA disease, compared them to CSR
recipients with left coronary artery (LCA)
ischemia and found that it was comparably
effective in alleviating angina and improving
QoL: there was no difference in improvement for
at least one CCS class between groups and QoL
domain of SAQ improved significantly more in
CTO RCA group [16]. Although further research
is required, current results suggest that, under
proper selection, CSR could also be of benefit to
patients with RCA disease. A detailed summary
of the efficacy of CSR in the included studies is
provided in Table 1.
3.3. Safety
The most common complication was hematoma
at the vascular access site with an incidence rate
of 8,9% [14]. The second most common -
periprocedural CSR embolization / dislocation
with an incidence rate ranging from 0,5% to
8,0% [8, 9, 12, 13, 15]. Other less common
complications included inability to deploy CSR,
failure to cannulate the coronary sinus (CS),
dissection or perforation of CS, cardiac
tamponade requiring pericardiocentesis and
myocardial infarction, possibly related to the
procedure and device [8, 9, 12, 15]. A detailed
summary of the safety of CSR in the included
studies is provided in Table 2.
3.4. Cost-effectiveness
Budget impact analysis revealed incremental
resource savings beginning in the third year after
the CSR implantation, which translated into a
total of 59 772,44 € saved over the time horizon
of 5 years. This resulted from the reduction in
consumed healthcare resources: hospitalizations,
specialist visits, emergency room accesses,
coronary examinations, and percutaneous
coronary interventions [17]. Cost-utility analysis
showed that even under both the assumptions of
a reducer effect duration for 2 and 3 years from
implant with a 30%-year efficacy decrease, the
Incremental Cost-Effectiveness Ratio (ICER)
(€/quality-adjusted life year (QALY)) became
dominant (meaning that the reducer device
turned out to be less expensive and more
effective than the Standard of Care (SoC))
starting from year 3 onward [17, 18]. Starting
from year 2, device implantation was cost-
effective as resulting ICERs were well below
both World Health Organization (WHO)
(defined as three times the national annual GDP
per capita) and 50 000 €/QALY thresholds [18].
4. Conclusions
Coronary sinus reducer is an efficient, safe and
cost-effective treatment of refractory angina. It is
associated with a significant reduction in angina
symptoms, an improvement in left ventricular
function, exercise tolerance and quality of life.
Redistribution of perfusion from subepicardial to
subendocardial myocardium in ischaemic
segments and improvement in coronary
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51
microcirculatory function parameters after
device implantation may underlie these effects.
The incidence of complications is modest, the
effect of the device is durable, and cost-
effectiveness is achieved within 2 years.
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Table 1. Summary of the efficacy of CSR in the included studies
Authors /
date
n
Type of study /
paper
Inclusion
criteria
Relevant outcomes
Results
Foley et al.
(ORBITA-
COSMIC)
(2024)
[15]
50
Multicentre,
randomised,
double-blind,
placebo-
controlled trial.
≥ 18 years old
patients with
angina,
epicardial
coronary artery
disease,
ischaemia, and
no further
options for
antianginal
therapy
1. Myocardial blood
flow on adenosine-
stress cardiac magnetic
resonance in
myocardial segments
designated as
ischaemic at enrolment
(excluding
transmurally infarcted
segments).
2. The number of daily
episodes of angina.
3. SAQ, MacNew
Heart Disease Health-
Related Quality of
Life, EQ-5D-5L index
values; CCS class.
At 6 - month follow-
up:
1. No benefit of CSR
over placebo was
detected in stress
myocardial blood flow
in segments designated
ischaemic at enrolment
(difference for CSR vs
placebo 0,06 mL/min
per g [95% CrI –0,09 to
0,20]).
2. Patients in the CSR
group were more likely
to have a lower number
of daily episodes of
angina (OR 1,40 [95%
CrI 1,08 to 1,83]).
3. Both SAQ angina
frequency and
MacNew Heart
Disease Health-
Related Quality of Life
scores improved in the
CSR group compared
with the placebo group;
no difference between
the groups was seen in
any other SAQ
domains, EQ-5D-5L
index value, CCS class.
Tebaldi et al.
(INROAD)
(2024)
[7]
24
Multicentre,
single-cohort,
investigator-
driven study.
≥ 18 years old
patients with the
diagnosis of
refractory angina
having at least 1
open coronary
artery (excluded
right coronary
artery) where to
perform invasive
coronary
physiological
assessment
1. Change of index of
microcirculation
resistance (IMR)
values from baseline to
follow-up.
2. Variation from
baseline to follow-up
of coronary flow
reserve (CFR).
3. Variation from
baseline to follow-up
of resistive resistance
ratio (RRR).
4. CCS class, SAQ
changes from baseline,
The Beck Depression
Inventory.
At 4 - month follow-
up:
1. A significant (≥20%
from baseline)
reduction of IMR was
observed in 71,4%
[95% CI, 47,8%–
88,7%]) patients.
2. CFR values did not
change significantly.
3. RRR values did not
change significantly.
4. A total of 42,8% and
76,1 % patients had an
improvement of at least
2 or 1 CCS class,
respectively; SAQ
summary score
increased by 4 points in
the IMR responders,
whereas it remained
unchanged in the IMR
nonresponders; no
significant changes in
Beck Depression
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Inventory values were
observed.
Ferreira Reis
et al.
(2023)
[8]
26
Multicentre,
prospective,
single-arm,
non-blinded
study.
Angina (at least
CCS class 2) no
further options
for antianginal
therapy, and
ischaemia
documented by
myocardial
stress single-
photon emission
computed
tomography
(SPECT) or
myocardial
stress magnetic
resonance
imaging (MRI)
attributable to
the left coronary
artery regardless
of the presence
of obstructive
epicardial CAD.
1. CCS class change.
2. Improvement in
QoL assessed by SAQ-
7.
3. Reduction in
number of antianginal
drugs.
At 6 - month follow-
up:
1. A total of 42,0% and
75,0% patients had an
improvement of at least
2 or 1 CCS class,
respectively; 16,7%
became asymptomatic.
2. All scales of the
SAQ-7 showed a
significant
improvement: the QoL
score improved by 20,2
points and summary
score improved by 16,6
points.
3. 54,0% discontinued
or had the dose reduced
of at least one anti-
ischemic drug.
D‘Amico et
al.
(2020)
[9]
187
Multicentre,
observational,
national, single
arm, non-
blinded study.
Patients
suffering from
chronic
disabling angina
pectoris (CCS
classes 2 to 4)
and no further
options for
antianginal
therapy
1. CSS class change.
2. Physical limitation,
angina stability and
frequency, treatment
satisfaction and quality
of life assessed by
SAQ.
3. Reduction in
number of antianginal
drugs.
At median follow-up of
18,4 months:
1. A total of 49,0% and
82,0% patients had an
improvement of at least
2 or 1 CCS class,
respectively.
2. Physical limitation
scores improved by
20,1 points, angina
stability scores
improved by 21,5
points, angina
frequency scores
improved by 25,5
points, treatment
satisfaction scores
improved by 27,8
points and quality of
life scores improved by
30,8 points.
3. Significant reduction
of anti-ischemic drugs
(mean number
2,77±1,04 vs 2,00±1,2,
p < 0,001). Detailed
distribution of changes
in number of
antianginal drugs was
not provided.
Tzanis et al.
(2020)
[10]
19
Single-centre,
prospective,
non-blinded
study.
Refractory
angina of at least
CCS class 2,
despite optimal
medical
1. CCS class change.
2. Change in LV
ejection fraction
(LVEF), LV end-
diastolic volume
At 4 - month follow-
up:
1. A total of 37,0% and
84,0% patients had an
improvement of at least
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55
treatment
(OMT) with
evidence of
inducible
myocardial
ischemia at
dipyridamole
stress cardiac
magnetic
resonance
(CMR) and no
further options
for antianginal
therapy.
(LVEDV),
LVEDV/body surface
area (BSA), LV end-
systolic volume
(LVESV) and
LVESV/BSA
measured using CMR.
3. Change in
transmural myocardial
perfusion reserve
index (MPRI).
2 or 1 CCS class,
respectively; An
improvement of 3 CSS
class was observed in
5,3% of patients.
2. A significant
improvement was
observed in:
• LVEF (61 [IQR 47–71]
to 66 [IQR 57–72] %; p
= 0,009). Improvement
was more pronounced
in patients with EF <
50% (11,3 [IQR 6,5–
54,5] vs. 3,8 [IQR 0,6–
9,1] %; p = 0,028)
• LVEDV (132,1 [IQR
118,0–173,6] to 123,0
[IQR 99,7–158,2]
mL; p = 0,033)
• LVEDV/BSA (65,7
[IQR 57,4–89,6] to
64,7 [IQR 53,7–74,1]
mL/m
2
; p = 0,036)
• LVESV (55,1 [IQR
37,7–75,3] to 41,2
[IQR 30,7–70,0] mL; p
= 0,007)
• LVESV/BSA (28,7
[IQR 18,6–38,8] to 20
[IQR 15,0–31,4]
mL/m
2
; p = 0,007).
3. A significant
increase in transmural
MPRI was observed
(p < 0,011). LVEDV
decrease was more
pronounced in patients
that improved the
MPRI values (p =
0,054).
Palmisano et
al.
(2020)
[11]
20
Single-centre,
single-arm,
prospective
observational
study.
Patients
suffering from
refractory angina
(classified at
least as CCS
class 2 despite
OMT) with
evidence of
CAD not
amenable to
revascularization
and having
inducible
myocardial
ischemia
involving at least
one myocardial
segment at
1. Change in LVEF,
LVEDV, LVESV and
indexed LV mass
measured using CMR.
2. Change in global
circumferential (GCS),
longitudinal (GLS)
and radial strain (GRS)
measured using CMR.
3. Modification of
peak diastolic strain
rate in circumferential,
radial, and
longitudinal
directions.
4. Changes in
myocardial structural
remodelling
At 4 - month follow-
up:
1. Significant
improvement in
median LVEF (from
61,0% to 67,0%;
p = 0,0079) was
observed. There were
no significant changes
in LVEDV, LVESV
and indexed LV mass
observed.
2. A significant
improvement of GCS
and GLS was observed
(GCS: − 18,0% vs –
21,0%; p = 0,0017;
GLS: − 16,0% vs –
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baseline stress-
CMR
parameters (native T1,
ECV, cellular and
matrix volume).
5. Changes of the
ischemic burden and
MPRI.
6. CCS class change.
7. SAQ score change.
8. Exercise tolerance
assessed by 6 minute
walk test (6 - MWT).
19,0%; p = 0,0192).
GRS slightly improved
without reaching
statistical significance
(GRS: 43,0% vs
48,0%, p = 0,0897).
3. No significant
modification of peak
diastolic strain rate was
observed in any
evaluated directions.
4. Structural
remodelling
parameters did not
change significantly.
5. Reduction of the
ischemic burden (13,0–
11,0%; p = 0,0135) and
improvement of the
MPRI (1,10 vs 1.30;
p = 0,0085) were
observed. MPRR
endo/epi ratio
increased significantly
in the ischaemic
segments.
6. A total of 35,0 % and
85,0 % patients had an
improvement of at least
2 or 1 CCS class,
respectively.
7. Significant
improvement in all
domains of SAQ was
observed.
8. Exercise tolerance
significantly improved
as assessed by 6 -
MWT: 305 [IQR 240–
386] vs 415 [IQR 322–
495] metres;
p = 0,0372
Mrak et al.
(2021)
[16]
46
Multicentre,
prospective,
observational
study.
Patients ≥ 18
years, refractory
angina with CCS
class 2 – 4
despite OMT at
maximally
tolerated doses,
obstructive CAD
without further
revascularization
options, and
objective
evidence of
reversible
ischemia as
assessed by
SPECT or CMR.
1. CCS class change:
difference between
patients with chronic
total occlusion (CTO)
of right coronary
artery (RCA) and
obstructive coronary
artery disease (CAD)
of left coronary artery
(LCA).
2. Improvement of
SAQ scores.
3. Reduction of
segments with
inducible ischemia in
patients with CTO
RCA.
At 12 - month follow-
up:
1. There was no
difference in CSS class
change comparing
patients with CTO of
RCA and obstructive
CAD of LAD:
improvement for at
least one CCS class
was noted in 77,2%
CTO RCA and 70,2%
LCA patients (p =
0,62). In a subgroup of
12 patients with
isolated CTO RCA
CCS class
improvement was
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57
comparable to CCS
class improvement in
the LCA group (p =
0,65); improvement for
at least one CCS class
was noted in 66,7%
patients.
2. All 5 SAQ domains
improved in all groups,
physical limitations
and QoL improved
significantly more in
the CTO RCA group (p
= 0,001 for both
domains).
3. The reduction of
segments with
inducible ischemia
observed in the CTO
RCA patients was not
significant (43 vs. 39
segments, p = 0,29).
There was, however, a
significant
improvement in both
the transmurality index
and the MPRI.
Verheye et
al.
(REDUCER-
I)
(2025)
[12]
361
Multicentre,
nonrandomized,
real-world
observational
study.
Patients with
refractory angina
despite OMT
and without
revascularization
options.
1. CCS class change.
2. QoL assessed by
SAQ, EQ-5D-5L and
EQ-VAS.
3. Changes in
functional capacity
assessed by 6 - MWT.
4. Treatment durability
assessed by
sustainability of
improvements in CCS
class and QoL through
3 years.
At 6 - month follow-
up:
1. A total of 24,1% and
69,8% patients had an
improvement of at least
2 or 1 CCS class,
respectively.
2. Significant
improvements in all
SAQ domains and in
overall EQ-VAS score
were observed;
similarly, assessed by
EQ-5D-5L, a
significant decrease in
the proportion of
patients with limited
mobility, with
limitations in their
usual activities, having
pain or discomfort, and
having anxiety or
depression was
observed.
3. Exercise tolerance
significantly improved
as assessed by 6 -
MWT: 325,2 ± 116,6
(263) m vs 359,0 ±
110,9 (268) m (p <
0,0001)
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At 3 - year follow-up:
4. The proportion of
CCS class III/IV
patients remained
below 20,0% (p <
0,0001). Similarly,
SAQ overall scores
remained above 60%
(p < 0,0001).
Włodarczak
et al.
(2024)
[13]
55
Single centre,
non-blinded,
real-life cohort
study.
Diagnosis of
chronic
refractory angina
CCS classes 2–4
for at least 3
months before
the procedure in
spite of
maximum
tolerable
medical therapy
for angina.
1. CCS class change.
2. Improvement of
QoL assessed by SAQ-
7.
3. Changes in
functional capacity
assessed by 6 - MWT.
At 3 - month follow-
up:
1. A total of 50,9 % and
90,9 % patients had an
improvement of at least
2 or 1 CCS class,
respectively; 9,1%
patients had an
improvement of 3 CCS
classes.
2. There was a
significant
improvement in SAQ-
7 total (39,2 ± 15,8 vs.
50,4 ± 20,5; p <
0,0001).
3. Exercise tolerance
significantly improved
as assessed by 6 -
MWT: 233,3 ± 107,1 m
vs. 305,2 ± 126,8 m; p
< 0,0001.
Włodarczak
et al.
(2025)
[14]
67
Single-centre,
single-arm
registry analysis
All consecutive
patients
diagnosed with
refractory angina
CCS classes 2-4
despite OMT,
who underwent
implantation of
the CSR in the
Department of
Cardiology of
the Copper
Health Center in
Lubin, Poland.
1. CCS class change.
2. Improvement of
QOL assessed by
SAQ-7.
3. Changes in
functional capacity
assessed by 6-MWT.
At 12 - month follow-
up:
1. A total of 86,6 %
patients had an
improvement of at least
1 CCS class.
2. There was a
significant
improvement in SAQ-
7 total score (39,9
[15,2] vs 54,6 [19,7], p
< 0,001).
3. A significant
improvement in
functional capacity
was observed as
assessed by 6 - MWT:
(265,9 [136,9] vs.
234,9 [109,1], p =
0,03)
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Table 2. Summary of the safety of CSR in the included studies
Authors / date
n
Type of adverse event
n (incidence)
Foley et al.
(ORBITA-
COSMIC)
(2024)
[15]
25
CSR embolization
2 (8,0%)
Inability to deploy CSR
1 (4,0%)
Ferreira Reis et
al.
(2023)
[8]
26
Failure to cannulate the CS
1 (3,8%)
Periprocedural CSR migration to the superior
vena cava requiring surgical retrieval
1 (3,8%)
Perforation of the CS with cardiac tamponade
requiring pericardiocentesis
1 (3,8%)
D‘Amico et al.
(2020)
[9]
187
CSR embolization
1 (0,5%)
CSR dislocation
4 (2,1%)
Coronary sinus dissection
1 (0,5%)
Coronary sinus perforation
2 (1,1%)
Inability to deploy CSR
2 (1,1%)
Verheye et al.
(REDUCER-I)
(2025)
[12]
371 (for
safety
endpoints
assessment)
CSR migration
3 (0,8%)
Cardiac tamponade treated with
pericardiocentesis
1 (0,3%)
Myocardial infarction (adjudicated as possibly
related the procedure and device)
1 (0,3%)
Włodarczak et al.
(2024)
[13]
55
Migration of the CSR into the pulmonary
arteries
1 (1,8%)
Włodarczak et al.
(2025)
[14]
67
Hematoma at the vascular access site
6 (8,9%)
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