Improved Survival With Automated External Defibrillator‐Only Training in a Public‐Access Defibrillation Program: A 23‐Year Database Analysis of Progetto Vita

Abstract

Background

Out‐of‐hospital cardiac arrest remains a significant public health challenge, characterized by poor overall survival. Early defibrillation is crucial to manage fatal arrhythmias. The use of automated external defibrillators is a promising tool in minimizing time to defibrillation and enhancing survival.

Methods

PV (Progetto Vita) in Piacenza pioneered the first community‐based automated external defibrillator project in Europe. We present survival data spanning 23 years for all cases of out‐of‐hospital cardiac arrest managed under both PV and standard emergency medical services interventions.

Results

A total of 6996 out‐of‐hospital cardiac arrests were recorded. Among these, 156 cases were managed by PV volunteers (PV group). The PV group managed a significantly higher proportion of shockable rhythms than the emergency medical services group (69.9% versus 10.9%). Mean time to arrival was shorter (5.7 versus 10.2 minutes), and survival rates better with favorable neurological outcomes (46.2% versus 2.9%, overall). Survival rates declined with time. However, a higher proportion of patients in the PV ‐group demonstrated favorable neurological outcomes, even up to 9 minutes from the call, compared with the EMS group. Over the study period, the increasing number of automated external defibrillators in fixed public places coincided with a substantial rise in ventricular fibrillation survival in the PV group patients (22% for 2003–2012 to 73% for 2013–2022, P<0.001). Both time from call to arrival and PV‐group intervention emerged as independent predictors of survival (odds ratio 1.08 and 0.28, respectively).

Conclusions

Our simplified automated external defibrillator‐focused training for community has shown higher survival rates and emerges as a highly successful strategy in a small city.

Nonstandard Abbreviations and Acronyms

BLS

basic life support

OHCA

out‐of‐hospital cardiac arrest

PV

Progetto Vita

Clinical Perspective.

What Is New?

• PV (Progetto Vita) in Piacenza was the first community‐based automated external defibrillator project in Europe training community responders with a simplified method focused on the usage of publicly accessible automated external defibrillators.

• In our population, PV lay responders achieved remarkable results thus underscoring the efficacy of a focused intervention consisting in rapid defibrillation.

What Are the Clinical Implications?

• Prompt defibrillation has shown outstanding survival outcomes. In the future, advancements in management strategies for out‐of‐hospital cardiac arrest will be needed to enhance widespread public awareness, optimize fixed automated external defibrillator locations, and foster comprehensive use of automated external defibrillators.

Out‐of‐hospital cardiac arrest (OHCA) poses a substantial public health challenge, affecting approximately 400 000 individuals in the United States and a comparable number in Europe. ¹ , ² The standard response times of emergency medical services (EMS) often result in patients being discovered in asystole or pulseless electrical activity, whereas shorter intervention time can find ventricular fibrillation (VF) or pulseless ventricular tachycardia, with better chances of survival. Consequently, administering defibrillation within the first few minutes of cardiac arrest can significantly increase survival rates to >50%. ³ , ⁴ , ⁵ This is why numerous communities have engaged in initiatives to mitigate response times. ⁴ , ⁵ , ⁶ However, the Lancet Commission on sudden cardiac death unequivocally acknowledges the unacceptability of survival rates for sudden cardiac death remaining <10% in most parts of the world, despite these advancements. In 2015, for the first time, the International Liaison Committee on Resuscitation guidelines strongly recommended the widespread implementation of public‐access defibrillation. ⁷ The most recent guidelines from the European Society of Cardiology for managing patients with ventricular arrhythmias and preventing sudden cardiac death, published in 2022, advocate early defibrillation as a Class I intervention with level of evidence B. ⁸

Automated external defibrillators (AEDs) represent a viable solution, easily and safely deployable by lay responders witnessing cardiac arrest, as well as by firefighters or police officers before the arrival of EMS personnel. The use of AEDs by such “first responders” or “onsite bystanders” holds tremendous potential for reducing time to defibrillation and further enhancing survival rates. ⁹ , ¹⁰ , ¹¹

Here we present the results of the 23‐year PV (Progetto Vita), the pioneering early defibrillation project established in Europe in 1999 in Piacenza, Italy. The project has grown organically over the past 23 years, providing training in early defibrillation to >130 000 citizen volunteers (45% of the population of Piacenza city and the surrounding county).

In this initiative, rapid defibrillation was the paramount element in saving victims of sudden cardiac arrest, and community responders were specifically trained with a simplified method focused on the usage of publicly accessible AEDs, with a motivational approach that emphasizes the role of lay responders. Particularly, training courses for the lay volunteers include 2 hours of theoretical and practical lessons. Four instructors train 16 volunteers during each session. Participants are instructed to recognize the absence of consciousness, note the absence of breathing, and check for signs of circulation. If none are present, they are instructed to turn on the AED and to follow the voice instructions of the AED. Easy instruction for cardiopulmonary resuscitation (CPR), precordial compression not ventilation, is provided. A final examination is also performed. The aim of the project was to minimize the time from collapse to shock administration, with more emphasis on the rapid use of AED than on CPR alone. ¹²

METHODS

The data that support the findings of this study are available from the corresponding author upon reasonable request.

The study was conducted according to the guidelines of the Declaration of Helsinki. Written informed consent was retrieved from all survivors.

Progetto Vita

The introduction of the first public AEDs in the community in Europe occurred with the inception of PV in 1999 in Piacenza, Italy. The project provided a simplified, ready‐to‐use option for effectively training laypeople in the use of AEDs. CPR was neither taught nor performed during OHCA by PV‐trained volunteers, in contrast to the standard approach followed by the city's EMS system. The original structure and organization of PV, along with early survival data until 2011, ¹³ have been previously documented. In the initial 3 years of PV (1999–2001), volunteer ambulance responders (ie, basic life support [BLS]) equipped with AEDs played a pivotal role in PV. ¹²

From June 1, 2001, Italian national law mandated the integration of all BLS volunteer ambulance responders under standard EMS control, necessitating adherence to the International Liaison Committee on Resuscitation guidelines. This article concentrates only on PV citizen responders not obliged to follow the standard national protocol (ie, BLS volunteer‐rescued patients are included in the EMS outcomes).

Currently, phone calls or the AED Responder App activate PV volunteers and the standard EMS system simultaneously. PV has progressively increased AED availability in Piacenza, from 21 in 1999 (supported by the Medtronic and Laerdal foundation) to 1161 by December 31, 2022 (1067 in public venues and 94 in police and firefighter vehicles) with a density of 1:251 inhabitants.

Since its inception, the AED protocol for PV has specified a shock sequence of 3 shocks and a 1‐minute pause, as established in the International Liaison Committee on Resuscitation guidelines in 2000. The EMS protocol has changed over time according to current guidelines (most recently to 1 shock and a 2‐minute pause).

Data Collection

OHCA in this analysis was defined by adherence to the Utstein reporting criteria, and syncope and other forms of transient loss of consciousness were excluded from the analysis. Data on the sex, age, location of cardiac arrest, and time from call to rescuers' arrival for the patients with OHCA were tabulated from PV and EMS data forms. The time at which the emergency telephone call was received, the departure time of the ambulance from the hospital, and the arrival time on the scene by both PV lay volunteers and EMS staff were recorded. The internal clocks of the AEDs were synchronized with the EMS Central Station. To ensure accuracy, the time from call to rescuers' arrival was cross‐verified by comparing rescuer‐recorded data with dispatcher phone calls. From 2003 onward, all data were digitally collected by the EMS dispatchers. ECGs from OHCA interventions were extracted from AED data cards, classifying arrests as asystole, pulseless electrical activity, or shockable rhythm (ventricular tachycardia or VF). Cases where the ECG was not available in our archives were classified as “unavailable.” This occurred in most cases in the phase before digital archiving of the data. OHCA cases were categorized as PV or standard EMS according on the controlling rescue team. Over the 23‐year period, survival with favorable neurological outcome (defined as Cerebral Performance Category 1 or 2) was documented for all OHCAs under both PV and EMS interventions. Geographical data from EMS forms were used in the analysis. An updated map of AED locations in Piacenza and an updated map of AEDs are accessible on the www.progetto‐vita.eu website. In our analysis of OHCA cases in Piacenza cityin 2022, a geographic information system (QGIS, http://www.qgis.org/en/site) was used to geocode event addresses. An AED was considered available if placed within 200 m of the OHCA location, based on the estimation that bystanders could transport it to the victim within 3 minutes.

Statistical Analysis

Distribution of continuous variables was described using mean±SD. Categorical variables were described using counts and percentages. A chi‐square test was used to compare dichotomous variables between the 2 groups. Nonparametric Wilcoxon test was used to compare median age of patients and time from dispatch to arrival on site between PV and EMS. A multivariable logistic regression was performed to assess the relationship between survival data in defibrillated patients and the explanatory variables: sex, age, location of cardiac arrest, initial responder, and time from cardiac arrest to first intervention. Data were checked for multicollinearity using the Belsley–Kuh–Welsch technique. Heteroskedasticity and normality of residuals were assessed respectively by the White test and the Shapiro–Wilk test. A P value of 0.05 was considered statistically significant. In Figure S1 survival analysis with log‐rank test for PV group and EMS group was performed. SPSS 13.0 for Windows (SPSS Inc, Chicago, IL) was used for the statistical analyses.

RESULTS

A total of 6996 OHCAs were documented in the Piacenza area from June 1, 1999 to December 31, 2022. Survival data from the hospital were available for all 6996 patients, and their characteristics are summarized in Table 1.

Table 1.

Demographic and Clinical Characteristics of Patients

Patient population	All	Progetto Vita	EMS	P value
No.	6996	156	6840
Median age, y	76.1±14.3	67.5±14.7	76.3±14.3	<0.001
Male sex	4011 (57.3%)	118 (75.6%)	3893 (56.9%)	<0.001
Location of cardiac arrest
Home	6165 (88.1%)	95 (60.9%)	6070 (88.7%)	<0.001
Public space	493 (7%)	36 (23.1%)	457 (6.7%)	<0.001
EMS intervention
Basic life support ambulance			3796 (55.5%)
Advanced cardiovascular life support ambulance			3044 (44.5%)
Presenting rhythm
Shockable rhythm	852 (12.2%)	109 (69.9%)	743 (10.9%)	<0.001
Nonshockable rhythm	3936 (56.3%)	38 (24.3%)	3898 (57%)	<0.001
Unavailable	2208 (31.5%)	9 (5.8%)	2199 (32.1%)
Time from sudden cardiac arrest to rescuers’ arrival (median±SD)	10±6.8	5.7±3.8	10.2±6.8	<0.001
Admitted to hospital	860 (12.2%)	92 (58.9%)	768 (11.2%)	<0.001
Survival with favorable neurologic outcome
Overall	268/6996 (3.8%)	72/156 (46.2%)	196/6840 (2.9%)	<0.001
Defibrillated patients	226/852 (26.5%)	70/109 (64.2%)	156/743 (20.9%)	<0.001

EMS indicates emergency medical services.

Patients rescued by PV lay responders were notably younger (67.5±14.7 versus 76.3±14.3 years; P<0.001) and predominantly male (75.6% versus 56.9%, P<0.001). PV rescuers were involved in a significantly higher proportion of OHCAs in public places than EMS (23.1% versus 6.7%; P<0.001). Shockable rhythms were observed in 69.9% of PV patients, a stark contrast to the 10.9% observed in EMS patients (P<0.001).

The mean time from dispatch to arrival differed significantly between events attended by PV volunteers and EMS, with values of 5.7±3.8 minutes and 10.2±6.8 minutes, respectively (P<0.001). The overall proportion of patients achieving 1‐month survival with a favorable neurological outcome was 3.8%. Among patients with shockable rhythms, the survival rate was 26.5% overall, exhibiting a remarkable difference between PV‐rescued patients and EMS patients (64.2% versus 20.9%, P<0.001). In Table S1 data of patients presenting with VF as the initial rhythm are reported. Figure 1 illustrates the correlation between the time elapsed from the emergency call to intervention and the survival rates of defibrillated patients. The black line represents the survival trend for the overall population, the red line depicts patients rescued by EMS, and the blue line represents patients rescued by PV volunteers. Notably, PV‐rescued patients who received defibrillation within 2 minutes of the emergency call exhibited a significantly higher survival rate of 75% compared with the 40% observed in EMS‐rescued patients (P=0.006).

Figure 1. Correlation between the time elapsed from the emergency call to intervention and the survival rates of defibrillated patients by type of intervention.

EMS indicates emergency medical services‐rescued patients; and PV, Progetto Vita‐rescued patients.

The survival rate globally decreased with an increased time from call to first shock. We observed a significantly higher proportion of survivors with favorable neurological outcomes even within 9 minutes from the call specifically in PV‐rescued patients (63% for PV‐rescued patients for 3–5 minutes versus 25% for EMS rescued; 54% for 6–9 minutes versus 15%, P<0.001 for both). Survival was lower in both groups and not statistically different if the shock was delivered >10 minutes after the call (25% for PV versus 14% for EMS, P=0.49).

Figure 2 shows the proportion of PV‐rescued and EMS‐rescued patients according to time (minutes) from call to first shock: 66% of all cases of PV‐defibrillated patients were treated within 5 minutes from EMS call versus 34% in the EMS group (mean 4.46±2.64 versus 8.11±5.39 minutes for PV and EMS groups, respectively, P<0.001). See Figure S1 for cumulative survival curves in patients with VF treated by PV and EMS.

Figure 2. Proportion of Progetto Vita‐rescued and emergency medical service‐rescued patients according to time (minutes) from call to first defibrillation.

EMS indicates emergency medical services‐rescued patients; and PV, Progetto Vita‐rescued patients.

Figure 3A shows the percentage of patients saved by fixed AEDs compared with patrol AEDs in the PV group for 5‐year study periods. The proportion of patients in whom an onsite AED was used increased, and the survival rate improved over time, mainly due to the use of an onsite AED rather than a mobile one. Figure 3B shows the percentage of patients saved from VF using a fixed AED according to the different rations of AEDs to inhabitants.

Figure 3. Patients (%) saved by onsite or mobile AEDs and patients saved from VF (%) treated by a fixed AED.

A, Patients (%) saved by onsite or mobile AEDs. The figure shows the percentage of patients saved by fixed AEDs (red bars) compared with patrol AEDs (yellow bars) in the PV group in 5‐year different study periods. Patients in whom an onsite AED was used increased and survival rate was progressively mainly due to the use of an onsite AED rather than a mobile one. B, Patients saved from VF (%) treated by a fixed AED. The figure shows the survival rates (%) of VF patients defibrillated using a fixed AED according to the different AEDs/inhabitants ratio. Since 2013, 100% of patients with VF treated with a fixed AED survived. AED indicates automated external defibrillator; and VF, ventricular fibrillation.

The subanalysis performed for 2022 indicated that 150 OHCAs occurred in the Piacenza urban area. The exact geographical location of 141 (94%) OHCAs was successfully determined. An AED was located within 200 m of a cardiac arrest in 67% (n=95) of all OHCAs but only 5% (n=5) of these had an AED applied.

Table 2 shows the results of the multivariate analysis of the age‐adjusted factors associated with 1‐month survival with favorable neurological outcome in defibrillated patients: cardiac arrest in public place (odds ratio [OR], 0.69 [95% CI, 0.43–1.14], P=0.15); time from cardiac arrest to first intervention (OR, 1.08 [95% CI, 1.03–1.13], P=0.0023); and PV intervention (OR, 0.28 [95% CI, 0.16–0.48], P<0.0001).

Table 2.

Multivariable Analysis of the Age‐Adjusted Factors Associated With 1‐Month Survival With Favorable Neurological Outcome in Defibrillated Patients

Variable	Odds ratio	P value
Cardiac arrest in public place	0.697 (0.426–1.14)	0.15
Progetto Vita intervention	0.282 (0.164–0.484)	<0.0001
Time from call to rescuers arrival	1.08 (1.03–1.13)	0.00232

DISCUSSION

In accordance with our previous reports, ¹² , ¹³ our data corroborate the efficacy of early defibrillation delivered by public‐access AEDs in enhancing survival for people with OHCA with shockable rhythms. In particular, the shorter arrival time when public AEDs are used results in better survival compared with EMS, even if AED use is trained with a simplified approach. In alignment with our previous reports, ¹³ the survival outcomes of PV underscore the effectiveness of a unique project focused on elevating resuscitation rates in a small Italian city with the swift use of public AEDs by bystanders only.

In our population, patients treated by PV lay responders were more frequently male, younger, and in a public place. The survival outcomes of events with equal time to intervention was better for the PV group compared with the EMS group. The time to the first intervention was significantly shorter in the PV group: 66% of PV‐defibrillated patients received treatment within 5 minutes of the cardiac arrest alarm. Our results, with a prolonged follow‐up, validate previous studies by providing evidence that delivering the AED shock earlier significantly improves outcomes and that the time from the call to the first intervention serves as an independent predictor of survival.

We observed an overall progressive decline in survival over time from the emergency call to arrival. However, a significantly higher survival rate was observed in the PV‐defibrillated group compared with EMS‐defibrillated patients (75% versus 40% within 2 minutes from OHCA recognition to intervention; 54% versus 25% for 3–5 minutes to intervention; 54% versus 15% for 6–9 minutes to intervention). In other words, it seems that the intervention of PV lay volunteers achieved better survival outcomes than EMS intervention, even independently of the time to intervention. Some demographic differences could, at least partially, account for this; however, the reported differences were quite substantial. As mentioned earlier, PV was initially designed for simplicity, aiming to streamline and expedite a citizen's response with a specific emphasis on early defibrillation through AED instruction only rather than CPR. We have previously observed that CPR performed after recovery of a spontaneous rhythm after defibrillation may provoke recurrence of VF, worsening the prognosis of patients. ¹⁴ Previous studies have proposed a 3‐phase, time‐sensitive model of cardiac arrest, ¹⁵ , ¹⁶ , ¹⁷ in which the earliest phase of OHCA is the electrical phase, effectively treatable with immediate electrical shock alone. This may offer a plausible explanation for the higher survival rates observed in PV‐rescued patients, indicating that early defibrillation is the primary factor in facilitating survival, whereas chest compressions play, at most, a secondary role.

Of note, as previously stated, the AED protocol for PV has a specified shock sequence of 3 shocks and a 1‐minute pause, whereas EMS uses 1 shock and a 2‐minute pause. This could offer a possible further explanation for the survival differences observed in the 2 groups at the same time of intervention.

Another important discovery of the reported results is associated with the heightened survival rate in PV‐defibrillated patients, aligning with the increased number of public‐access AEDs in our province. Particularly, we observed a significant surge in 1‐month neurologically intact survival in the PV group since 2013 (22% in the 2003–2012 period increasing to 73% for 2013–2022, ratio of AEDs to inhabitants 1:170 in 2022). In 1999, a limited number of AEDs were strategically placed in fixed locations such as main public squares, the university, the stadium, athletic centers, the post office, and the railway station. Mobile AEDs were also placed in selected vehicles (police, firefighter vehicles, etc.). Subsequently, AEDs have been widely installed in nearly every street of the city and in numerous private shops and pharmacies, thanks to the involvement of the community and private entities providing financial support to the project. The challenge remains that after 23 years, as prominently observed, PVhas an intervention rate of only 2.2% of all cardiac arrests. The differences in the characteristics of the population treated by PV volunteers compared with the EMS group indicate that in public spaces the intervention occurs more frequently in favor of male and younger individuals, possibly indicating population concerns about treating older or female subjects.

In 2022, limiting the analysis to Piacenza city, where AED coverage is higher than in the remaining rural parts of the county, we observed an increased PV intervention rate to 5%. In 91 OHCA cases (61% of all OHCA cases in Piacenza city in 2022) an AED was available within 200 m of the OHCA location. To enhance AED use soon, persistent efforts are required to raise public awareness of the locations of fixed AEDs, promote nearby lay first‐responder app notification alerts, and establish a connection with the EMS dispatcher to guide bystanders to the nearest AED. This can be facilitated through the easily identifiable AED‐Responders app derived from the Piacenza PV app, currently operational in our region. Although increased AED awareness and accessibility are crucial, our findings also suggest that sociocultural factors likely contribute to the persistent underuse of AEDs—particularly in relation to age and sex disparities. For instance, reluctance to expose the chest of female victims due to modesty concerns or fear of legal repercussions may inhibit lay responders from acting, even when an AED is nearby. These issues are not solved by awareness campaigns alone. To address such barriers, additional measures are necessary, including sex‐sensitive training, targeted educational messaging, and open community discussions aimed at reducing discomfort and clarifying legal protections. These steps could help bridge the gap between AED availability and actual use in diverse segments of the population. Ideally, widespread access to home AEDs by the public would contribute significantly to improving survival rates in this highly unpredictable and life‐threatening disorder.

LIMITATIONS

This study has some limitations. First, the small number of interventions in the PV group. This is due to the fact that the interventions carried out by the PV group depend largely on the number of AEDs in public spaces. Although our work has an observation duration of >20 years, the number of defibrillators in public spaces has undergone a significant increase only in more recent years. Moreover, there are differences in the populations treated by PV and EMS. However, the outcomes of the 2 approaches exhibit substantial differences, appearing to depend more on the intervention style than demographics, despite the population variances. Finally, a notable limitation is the evaluation of 2 distinct interventional approaches in a nonrandomized comparison. Ideally, a randomized trial should compare a shock‐only approach with a full BLS/advanced cardiovascular life support approach in both response groups. Although ideal scientifically, implementing such trial within the current BLS/advanced cardiovascular life support paradigm would be challenging. We argue that the outcomes with the PV approach should not be easily dismissed, given the excellent results observed in those promptly shocked by lay volunteers without performing CPR.

CONCLUSIONS

A simplified approach to OHCA resuscitation by lay people, emphasizing prompt defibrillation from public‐access AEDs, demonstrates outstanding survival outcomes. Our findings, particularly from the PV initiative, underscore the efficacy of such a focused intervention, with lay responders achieving remarkable results. Nevertheless, sustained efforts are imperative to enhance widespread public awareness, optimize fixed AED locations, and foster comprehensive use of AEDs. The success observed in our study advocates for continued advancements in OHCA management strategies, promoting the crucial role of early defibrillation by lay individuals in saving lives.

Sources of Funding

Progetto Vita is supported by citizens' charitable donation.

Disclosures

None.

Supporting information

Table S1

Figure S1